diff --git a/cms/djangoapps/contentstore/config/forms.py b/cms/djangoapps/contentstore/config/forms.py
index b233e4f498..f68c7441f2 100644
--- a/cms/djangoapps/contentstore/config/forms.py
+++ b/cms/djangoapps/contentstore/config/forms.py
@@ -4,13 +4,13 @@ Defines a form for providing validation.
 import logging
 
 from django import forms
+from opaque_keys import InvalidKeyError
+from opaque_keys.edx.locator import CourseLocator
+from six import text_type
 
 from contentstore.config.models import CourseNewAssetsPageFlag
-
-from opaque_keys import InvalidKeyError
-from six import text_type
+from openedx.core.lib.courses import clean_course_id
 from xmodule.modulestore.django import modulestore
-from opaque_keys.edx.locator import CourseLocator
 
 log = logging.getLogger(__name__)
 
@@ -23,16 +23,7 @@ class CourseNewAssetsPageAdminForm(forms.ModelForm):
         fields = '__all__'
 
     def clean_course_id(self):
-        """Validate the course id"""
-        cleaned_id = self.cleaned_data["course_id"]
-        try:
-            course_key = CourseLocator.from_string(cleaned_id)
-        except InvalidKeyError:
-            msg = u'Course id invalid. Entered course id was: "{0}."'.format(cleaned_id)
-            raise forms.ValidationError(msg)
-
-        if not modulestore().has_course(course_key):
-            msg = u'Course not found. Entered course id was: "{0}". '.format(text_type(course_key))
-            raise forms.ValidationError(msg)
-
-        return course_key
+        """
+        Validate the course id
+        """
+        return clean_course_id(self)
diff --git a/cms/djangoapps/xblock_config/forms.py b/cms/djangoapps/xblock_config/forms.py
index 4ee49b1a60..70d91623f9 100644
--- a/cms/djangoapps/xblock_config/forms.py
+++ b/cms/djangoapps/xblock_config/forms.py
@@ -7,6 +7,7 @@ from django import forms
 from opaque_keys import InvalidKeyError
 from opaque_keys.edx.locator import CourseLocator
 
+from openedx.core.lib.courses import clean_course_id
 from xblock_config.models import CourseEditLTIFieldsEnabledFlag
 from xmodule.modulestore.django import modulestore
 
@@ -26,19 +27,4 @@ class CourseEditLTIFieldsEnabledAdminForm(forms.ModelForm):
         """
         Validate the course id
         """
-        cleaned_id = self.cleaned_data["course_id"]
-        try:
-            course_key = CourseLocator.from_string(cleaned_id)
-        except InvalidKeyError:
-            msg = u'Course id invalid. Entered course id was: "{course_id}."'.format(
-                course_id=cleaned_id
-            )
-            raise forms.ValidationError(msg)
-
-        if not modulestore().has_course(course_key):
-            msg = u'Course not found. Entered course id was: "{course_key}". '.format(
-                course_key=unicode(course_key)
-            )
-            raise forms.ValidationError(msg)
-
-        return course_key
+        return clean_course_id(self)
diff --git a/common/djangoapps/course_modes/admin.py b/common/djangoapps/course_modes/admin.py
index 2fc3b99a1c..6687f35d66 100644
--- a/common/djangoapps/course_modes/admin.py
+++ b/common/djangoapps/course_modes/admin.py
@@ -1,6 +1,7 @@
 from django import forms
 from django.conf import settings
 from django.contrib import admin
+from django.http.request import QueryDict
 from django.utils.translation import ugettext_lazy as _
 from opaque_keys import InvalidKeyError
 from opaque_keys.edx.keys import CourseKey
@@ -18,6 +19,7 @@ from course_modes.models import CourseMode, CourseModeExpirationConfig
 # but the test suite for Studio will fail because
 # the verification deadline table won't exist.
 from lms.djangoapps.verify_student import models as verification_models
+from openedx.core.lib.courses import clean_course_id
 from util.date_utils import get_time_display
 from xmodule.modulestore.django import modulestore
 
@@ -51,10 +53,23 @@ class CourseModeForm(forms.ModelForm):
     )
 
     def __init__(self, *args, **kwargs):
+        # If args is a QueryDict, then the ModelForm addition request came in as a POST with a course ID string.
+        # Change the course ID string to a CourseLocator object by copying the QueryDict to make it mutable.
+        if len(args) > 0 and 'course' in args[0] and isinstance(args[0], QueryDict):
+            args_copy = args[0].copy()
+            args_copy['course'] = CourseKey.from_string(args_copy['course'])
+            args = [args_copy]
+
         super(CourseModeForm, self).__init__(*args, **kwargs)
 
-        if self.data.get('course'):
-            self.data['course'] = CourseKey.from_string(self.data['course'])
+        try:
+            if self.data.get('course'):
+                self.data['course'] = CourseKey.from_string(self.data['course'])
+        except AttributeError:
+            # Change the course ID string to a CourseLocator.
+            # On a POST request, self.data is a QueryDict and is immutable - so this code will fail.
+            # However, the args copy above before the super() call handles this case.
+            pass
 
         default_tz = timezone(settings.TIME_ZONE)
 
@@ -78,16 +93,10 @@ class CourseModeForm(forms.ModelForm):
             )
 
     def clean_course_id(self):
-        course_id = self.cleaned_data['course']
-        try:
-            course_key = CourseKey.from_string(course_id)
-        except InvalidKeyError:
-            raise forms.ValidationError("Cannot make a valid CourseKey from id {}!".format(course_id))
-
-        if not modulestore().has_course(course_key):
-            raise forms.ValidationError("Cannot find course with id {} in the modulestore".format(course_id))
-
-        return course_key
+        """
+        Validate the course id
+        """
+        return clean_course_id(self)
 
     def clean__expiration_datetime(self):
         """
diff --git a/common/djangoapps/course_modes/models.py b/common/djangoapps/course_modes/models.py
index 62edaa074d..ac93241157 100644
--- a/common/djangoapps/course_modes/models.py
+++ b/common/djangoapps/course_modes/models.py
@@ -202,6 +202,9 @@ class CourseMode(models.Model):
         # Ensure currency is always lowercase.
         self.clean()  # ensure object-level validation is performed before we save.
         self.currency = self.currency.lower()
+        if self.id is None:
+            # If this model has no primary key at save time, it needs to be force-inserted.
+            force_insert = True
         super(CourseMode, self).save(force_insert, force_update, using)
 
     @property
diff --git a/common/djangoapps/student/admin.py b/common/djangoapps/student/admin.py
index 60ddb548bd..fdde9d00f1 100644
--- a/common/djangoapps/student/admin.py
+++ b/common/djangoapps/student/admin.py
@@ -9,6 +9,7 @@ from django.utils.translation import ugettext_lazy as _
 from opaque_keys import InvalidKeyError
 from opaque_keys.edx.keys import CourseKey
 
+from openedx.core.lib.courses import clean_course_id
 from student.models import (
     CourseAccessRole,
     CourseEnrollment,
@@ -41,23 +42,10 @@ class CourseAccessRoleForm(forms.ModelForm):
 
     def clean_course_id(self):
         """
-        Checking course-id format and course exists in module store.
-        This field can be null.
+        Validate the course id
         """
         if self.cleaned_data['course_id']:
-            course_id = self.cleaned_data['course_id']
-
-            try:
-                course_key = CourseKey.from_string(course_id)
-            except InvalidKeyError:
-                raise forms.ValidationError(u"Invalid CourseID. Please check the format and re-try.")
-
-            if not modulestore().has_course(course_key):
-                raise forms.ValidationError(u"Cannot find course with id {} in the modulestore".format(course_id))
-
-            return course_key
-
-        return None
+            return clean_course_id(self)
 
     def clean_org(self):
         """If org and course-id exists then Check organization name
diff --git a/common/djangoapps/student/tests/test_admin_views.py b/common/djangoapps/student/tests/test_admin_views.py
index d5886dfed0..980ffcc2b0 100644
--- a/common/djangoapps/student/tests/test_admin_views.py
+++ b/common/djangoapps/student/tests/test_admin_views.py
@@ -124,7 +124,7 @@ class AdminCourseRolesPageTest(SharedModuleStoreTestCase):
         response = self.client.post(reverse('admin:student_courseaccessrole_add'), data=data)
         self.assertContains(
             response,
-            'Cannot find course with id {} in the modulestore'.format(
+            'Course not found. Entered course id was: "{}".'.format(
                 course
             )
         )
diff --git a/common/djangoapps/student/tests/test_email.py b/common/djangoapps/student/tests/test_email.py
index 36e0c2ce1c..67478c0eea 100644
--- a/common/djangoapps/student/tests/test_email.py
+++ b/common/djangoapps/student/tests/test_email.py
@@ -16,6 +16,7 @@ from mock import Mock, patch
 from edxmako.shortcuts import render_to_string
 from openedx.core.djangoapps.site_configuration import helpers as configuration_helpers
 from openedx.core.djangoapps.theming.tests.test_util import with_comprehensive_theme
+from openedx.core.djangolib.testing.utils import CacheIsolationTestCase, CacheIsolationMixin
 from student.models import PendingEmailChange, Registration, UserProfile
 from student.tests.factories import PendingEmailChangeFactory, RegistrationFactory, UserFactory
 from student.views import (
@@ -84,7 +85,7 @@ class EmailTestMixin(object):
 
 
 @unittest.skipUnless(settings.ROOT_URLCONF == 'lms.urls', 'Test only valid in lms')
-class ActivationEmailTests(TestCase):
+class ActivationEmailTests(CacheIsolationTestCase):
     """
     Test sending of the activation email.
     """
@@ -164,7 +165,7 @@ class ActivationEmailTests(TestCase):
 
 @patch('student.views.login.render_to_string', Mock(side_effect=mock_render_to_string, autospec=True))
 @patch('django.contrib.auth.models.User.email_user')
-class ReactivationEmailTests(EmailTestMixin, TestCase):
+class ReactivationEmailTests(EmailTestMixin, CacheIsolationTestCase):
     """
     Test sending a reactivation email to a user
     """
@@ -241,7 +242,7 @@ class ReactivationEmailTests(EmailTestMixin, TestCase):
         self.assertTrue(response_data['success'])
 
 
-class EmailChangeRequestTests(EventTestMixin, TestCase):
+class EmailChangeRequestTests(EventTestMixin, CacheIsolationTestCase):
     """
     Test changing a user's email address
     """
@@ -365,12 +366,14 @@ class EmailChangeRequestTests(EventTestMixin, TestCase):
 @patch('django.contrib.auth.models.User.email_user')
 @patch('student.views.management.render_to_response', Mock(side_effect=mock_render_to_response, autospec=True))
 @patch('student.views.management.render_to_string', Mock(side_effect=mock_render_to_string, autospec=True))
-class EmailChangeConfirmationTests(EmailTestMixin, TransactionTestCase):
+class EmailChangeConfirmationTests(EmailTestMixin, CacheIsolationMixin, TransactionTestCase):
     """
     Test that confirmation of email change requests function even in the face of exceptions thrown while sending email
     """
     def setUp(self):
         super(EmailChangeConfirmationTests, self).setUp()
+        self.clear_caches()
+        self.addCleanup(self.clear_caches)
         self.user = UserFactory.create()
         self.profile = UserProfile.objects.get(user=self.user)
         self.req_factory = RequestFactory()
@@ -380,6 +383,16 @@ class EmailChangeConfirmationTests(EmailTestMixin, TransactionTestCase):
         self.pending_change_request = PendingEmailChangeFactory.create(user=self.user)
         self.key = self.pending_change_request.activation_key
 
+    @classmethod
+    def setUpClass(cls):
+        super(EmailChangeConfirmationTests, cls).setUpClass()
+        cls.start_cache_isolation()
+
+    @classmethod
+    def tearDownClass(cls):
+        cls.end_cache_isolation()
+        super(EmailChangeConfirmationTests, cls).tearDownClass()
+
     def assertRolledBack(self):
         """
         Assert that no changes to user, profile, or pending email have been made to the db
diff --git a/lms/djangoapps/bulk_email/forms.py b/lms/djangoapps/bulk_email/forms.py
index db3d1b24bf..17427c6a7a 100644
--- a/lms/djangoapps/bulk_email/forms.py
+++ b/lms/djangoapps/bulk_email/forms.py
@@ -10,6 +10,7 @@ from opaque_keys.edx.keys import CourseKey
 from six import text_type
 
 from bulk_email.models import COURSE_EMAIL_MESSAGE_BODY_TAG, CourseAuthorization, CourseEmailTemplate
+from openedx.core.lib.courses import clean_course_id
 from xmodule.modulestore.django import modulestore
 
 log = logging.getLogger(__name__)
@@ -79,20 +80,7 @@ class CourseAuthorizationAdminForm(forms.ModelForm):
         fields = '__all__'
 
     def clean_course_id(self):
-        """Validate the course id"""
-        cleaned_id = self.cleaned_data["course_id"]
-        try:
-            course_key = CourseKey.from_string(cleaned_id)
-        except InvalidKeyError:
-            msg = u'Course id invalid.'
-            msg += u' --- Entered course id was: "{0}". '.format(cleaned_id)
-            msg += 'Please recheck that you have supplied a valid course id.'
-            raise forms.ValidationError(msg)
-
-        if not modulestore().has_course(course_key):
-            msg = u'COURSE NOT FOUND'
-            msg += u' --- Entered course id was: "{0}". '.format(text_type(course_key))
-            msg += 'Please recheck that you have supplied a valid course id.'
-            raise forms.ValidationError(msg)
-
-        return course_key
+        """
+        Validate the course id
+        """
+        return clean_course_id(self)
diff --git a/lms/djangoapps/bulk_email/tests/test_forms.py b/lms/djangoapps/bulk_email/tests/test_forms.py
index 7bf95f69ab..91948023d4 100644
--- a/lms/djangoapps/bulk_email/tests/test_forms.py
+++ b/lms/djangoapps/bulk_email/tests/test_forms.py
@@ -78,9 +78,8 @@ class CourseAuthorizationFormTest(ModuleStoreTestCase):
         # Validation shouldn't work
         self.assertFalse(form.is_valid())
 
-        msg = u'COURSE NOT FOUND'
-        msg += u' --- Entered course id was: "{0}". '.format(text_type(bad_id))
-        msg += 'Please recheck that you have supplied a valid course id.'
+        msg = u'Course not found.'
+        msg += u' Entered course id was: "{0}".'.format(text_type(bad_id))
         self.assertEquals(msg, form._errors['course_id'][0])  # pylint: disable=protected-access
 
         with self.assertRaisesRegexp(
@@ -96,8 +95,7 @@ class CourseAuthorizationFormTest(ModuleStoreTestCase):
         self.assertFalse(form.is_valid())
 
         msg = u'Course id invalid.'
-        msg += u' --- Entered course id was: "asd::**!@#$%^&*())//foobar!!". '
-        msg += 'Please recheck that you have supplied a valid course id.'
+        msg += u' Entered course id was: "asd::**!@#$%^&*())//foobar!!".'
         self.assertEquals(msg, form._errors['course_id'][0])  # pylint: disable=protected-access
 
         with self.assertRaisesRegexp(
@@ -114,8 +112,7 @@ class CourseAuthorizationFormTest(ModuleStoreTestCase):
         self.assertFalse(form.is_valid())
 
         error_msg = form._errors['course_id'][0]  # pylint: disable=protected-access
-        self.assertIn(u'--- Entered course id was: "{0}". '.format(self.course.id.run), error_msg)
-        self.assertIn(u'Please recheck that you have supplied a valid course id.', error_msg)
+        self.assertIn(u'Entered course id was: "{0}".'.format(self.course.id.run), error_msg)
 
         with self.assertRaisesRegexp(
             ValueError,
diff --git a/lms/djangoapps/course_api/blocks/tests/test_api.py b/lms/djangoapps/course_api/blocks/tests/test_api.py
index 3c3d3eef08..913bc1a085 100644
--- a/lms/djangoapps/course_api/blocks/tests/test_api.py
+++ b/lms/djangoapps/course_api/blocks/tests/test_api.py
@@ -5,8 +5,8 @@ Tests for Blocks api.py
 from itertools import product
 
 import ddt
+import django
 from django.test.client import RequestFactory
-
 from openedx.core.djangoapps.content.block_structure.api import clear_course_from_cache
 from openedx.core.djangoapps.content.block_structure.config import STORAGE_BACKING_FOR_CACHE, waffle
 from student.tests.factories import UserFactory
@@ -161,8 +161,20 @@ class TestGetBlocksQueryCounts(SharedModuleStoreTestCase):
         with waffle().override(STORAGE_BACKING_FOR_CACHE, active=with_storage_backing):
             course = self._create_course(store_type)
             clear_course_from_cache(course.id)
+
+            if with_storage_backing:
+                # TODO: Remove Django 1.11 upgrade shim
+                # SHIM: Django 1.11 results in a few more SAVEPOINTs due to:
+                # https://github.com/django/django/commit/d44afd88#diff-5b0dda5eb9a242c15879dc9cd2121379L485
+                if django.VERSION >= (1, 11):
+                    num_sql_queries = 16
+                else:
+                    num_sql_queries = 14
+            else:
+                num_sql_queries = 6
+
             self._get_blocks(
                 course,
                 expected_mongo_queries,
-                expected_sql_queries=14 if with_storage_backing else 6,
+                expected_sql_queries=num_sql_queries,
             )
diff --git a/lms/djangoapps/course_goals/api.py b/lms/djangoapps/course_goals/api.py
index 3d05885f52..f1a65c0e2b 100644
--- a/lms/djangoapps/course_goals/api.py
+++ b/lms/djangoapps/course_goals/api.py
@@ -2,6 +2,7 @@
 Course Goals Python API
 """
 import models
+from six import text_type
 
 from opaque_keys.edx.keys import CourseKey
 from django.conf import settings
@@ -22,7 +23,7 @@ def add_course_goal(user, course_id, goal_key):
         goal_key (string): The goal key for the new goal.
 
     """
-    course_key = CourseKey.from_string(str(course_id))
+    course_key = CourseKey.from_string(text_type(course_id))
     current_goal = get_course_goal(user, course_key)
     if current_goal:
         # If a course goal already exists, simply update it.
diff --git a/lms/djangoapps/experiments/views.py b/lms/djangoapps/experiments/views.py
index 90758e3746..e26ce73d1c 100644
--- a/lms/djangoapps/experiments/views.py
+++ b/lms/djangoapps/experiments/views.py
@@ -46,7 +46,6 @@ class ExperimentDataViewSet(viewsets.ModelViewSet):
             try:
                 obj = self.get_queryset().get(user=self.request.user, experiment_id=experiment_id, key=key)
                 self.kwargs['pk'] = obj.pk
-                self.request.data['id'] = obj.pk
                 return self.update(request, *args, **kwargs)
             except ExperimentData.DoesNotExist:
                 pass
diff --git a/lms/djangoapps/grades/config/forms.py b/lms/djangoapps/grades/config/forms.py
index 4c72b57995..31457ea97c 100644
--- a/lms/djangoapps/grades/config/forms.py
+++ b/lms/djangoapps/grades/config/forms.py
@@ -9,6 +9,7 @@ from opaque_keys.edx.locator import CourseLocator
 from six import text_type
 
 from lms.djangoapps.grades.config.models import CoursePersistentGradesFlag
+from openedx.core.lib.courses import clean_course_id
 from xmodule.modulestore.django import modulestore
 
 log = logging.getLogger(__name__)
@@ -22,16 +23,7 @@ class CoursePersistentGradesAdminForm(forms.ModelForm):
         fields = '__all__'
 
     def clean_course_id(self):
-        """Validate the course id"""
-        cleaned_id = self.cleaned_data["course_id"]
-        try:
-            course_key = CourseLocator.from_string(cleaned_id)
-        except InvalidKeyError:
-            msg = u'Course id invalid. Entered course id was: "{0}."'.format(cleaned_id)
-            raise forms.ValidationError(msg)
-
-        if not modulestore().has_course(course_key):
-            msg = u'Course not found. Entered course id was: "{0}". '.format(text_type(course_key))
-            raise forms.ValidationError(msg)
-
-        return course_key
+        """
+        Validate the course id
+        """
+        return clean_course_id(self)
diff --git a/lms/djangoapps/grades/tests/test_course_grade_factory.py b/lms/djangoapps/grades/tests/test_course_grade_factory.py
index cc2e8c683a..c762899bb1 100644
--- a/lms/djangoapps/grades/tests/test_course_grade_factory.py
+++ b/lms/djangoapps/grades/tests/test_course_grade_factory.py
@@ -2,6 +2,7 @@ import itertools
 from nose.plugins.attrib import attr
 
 import ddt
+import django
 from courseware.access import has_access
 from django.conf import settings
 from lms.djangoapps.grades.config.tests.utils import persistent_grades_feature_flags
@@ -94,25 +95,57 @@ class TestCourseGradeFactory(GradeTestBase):
         with self.assertNumQueries(2), mock_get_score(1, 2):
             _assert_read(expected_pass=False, expected_percent=0)  # start off with grade of 0
 
-        with self.assertNumQueries(29), mock_get_score(1, 2):
+        # TODO: Remove Django 1.11 upgrade shim
+        # SHIM: Django 1.11 results in a few more SAVEPOINTs due to:
+        # https://github.com/django/django/commit/d44afd88#diff-5b0dda5eb9a242c15879dc9cd2121379L485
+        if django.VERSION >= (1, 11):
+            num_queries = 37
+        else:
+            num_queries = 29
+
+        with self.assertNumQueries(num_queries), mock_get_score(1, 2):
             grade_factory.update(self.request.user, self.course, force_update_subsections=True)
 
         with self.assertNumQueries(2):
             _assert_read(expected_pass=True, expected_percent=0.5)  # updated to grade of .5
 
-        with self.assertNumQueries(4), mock_get_score(1, 4):
+        # TODO: Remove Django 1.11 upgrade shim
+        # SHIM: Django 1.11 results in a few more SAVEPOINTs due to:
+        # https://github.com/django/django/commit/d44afd88#diff-5b0dda5eb9a242c15879dc9cd2121379L485
+        if django.VERSION >= (1, 11):
+            num_queries = 6
+        else:
+            num_queries = 4
+
+        with self.assertNumQueries(num_queries), mock_get_score(1, 4):
             grade_factory.update(self.request.user, self.course, force_update_subsections=False)
 
         with self.assertNumQueries(2):
             _assert_read(expected_pass=True, expected_percent=0.5)  # NOT updated to grade of .25
 
-        with self.assertNumQueries(12), mock_get_score(2, 2):
+        # TODO: Remove Django 1.11 upgrade shim
+        # SHIM: Django 1.11 results in a few more SAVEPOINTs due to:
+        # https://github.com/django/django/commit/d44afd88#diff-5b0dda5eb9a242c15879dc9cd2121379L485
+        if django.VERSION >= (1, 11):
+            num_queries = 20
+        else:
+            num_queries = 12
+
+        with self.assertNumQueries(num_queries), mock_get_score(2, 2):
             grade_factory.update(self.request.user, self.course, force_update_subsections=True)
 
         with self.assertNumQueries(2):
             _assert_read(expected_pass=True, expected_percent=1.0)  # updated to grade of 1.0
 
-        with self.assertNumQueries(12), mock_get_score(0, 0):  # the subsection now is worth zero
+        # TODO: Remove Django 1.11 upgrade shim
+        # SHIM: Django 1.11 results in a few more SAVEPOINTs due to:
+        # https://github.com/django/django/commit/d44afd88#diff-5b0dda5eb9a242c15879dc9cd2121379L485
+        if django.VERSION >= (1, 11):
+            num_queries = 20
+        else:
+            num_queries = 12
+
+        with self.assertNumQueries(num_queries), mock_get_score(0, 0):  # the subsection now is worth zero
             grade_factory.update(self.request.user, self.course, force_update_subsections=True)
 
         with self.assertNumQueries(2):
diff --git a/lms/djangoapps/grades/tests/test_tasks.py b/lms/djangoapps/grades/tests/test_tasks.py
index 21e46e9eb1..763b6d20a4 100644
--- a/lms/djangoapps/grades/tests/test_tasks.py
+++ b/lms/djangoapps/grades/tests/test_tasks.py
@@ -10,6 +10,7 @@ from datetime import datetime, timedelta
 import ddt
 import pytz
 import six
+import django
 from django.conf import settings
 from django.db.utils import IntegrityError
 from mock import MagicMock, patch
@@ -107,6 +108,28 @@ class HasCourseWithProblemsMixin(object):
         # pylint: enable=attribute-defined-outside-init,no-member
 
 
+# TODO: Remove Django 1.11 upgrade shim
+# SHIM: Django 1.11 results in a few more SAVEPOINTs due to:
+# https://github.com/django/django/commit/d44afd88#diff-5b0dda5eb9a242c15879dc9cd2121379L485
+# Get rid of this logic post-upgrade.
+def _recalc_expected_query_counts():
+    if django.VERSION >= (1, 11):
+        return 27
+    else:
+        return 23
+
+
+# TODO: Remove Django 1.11 upgrade shim
+# SHIM: Django 1.11 results in a few more SAVEPOINTs due to:
+# https://github.com/django/django/commit/d44afd88#diff-5b0dda5eb9a242c15879dc9cd2121379L485
+# Get rid of this logic post-upgrade.
+def _recalc_persistent_expected_query_counts():
+    if django.VERSION >= (1, 11):
+        return 28
+    else:
+        return 24
+
+
 @patch.dict(settings.FEATURES, {'PERSISTENT_GRADES_ENABLED_FOR_ALL_TESTS': False})
 @ddt.ddt
 class RecalculateSubsectionGradeTest(HasCourseWithProblemsMixin, ModuleStoreTestCase):
@@ -164,10 +187,10 @@ class RecalculateSubsectionGradeTest(HasCourseWithProblemsMixin, ModuleStoreTest
             self.assertEquals(mock_block_structure_create.call_count, 1)
 
     @ddt.data(
-        (ModuleStoreEnum.Type.mongo, 1, 23, True),
-        (ModuleStoreEnum.Type.mongo, 1, 23, False),
-        (ModuleStoreEnum.Type.split, 3, 23, True),
-        (ModuleStoreEnum.Type.split, 3, 23, False),
+        (ModuleStoreEnum.Type.mongo, 1, _recalc_expected_query_counts(), True),
+        (ModuleStoreEnum.Type.mongo, 1, _recalc_expected_query_counts(), False),
+        (ModuleStoreEnum.Type.split, 3, _recalc_expected_query_counts(), True),
+        (ModuleStoreEnum.Type.split, 3, _recalc_expected_query_counts(), False),
     )
     @ddt.unpack
     def test_query_counts(self, default_store, num_mongo_calls, num_sql_calls, create_multiple_subsections):
@@ -179,8 +202,8 @@ class RecalculateSubsectionGradeTest(HasCourseWithProblemsMixin, ModuleStoreTest
                     self._apply_recalculate_subsection_grade()
 
     @ddt.data(
-        (ModuleStoreEnum.Type.mongo, 1, 23),
-        (ModuleStoreEnum.Type.split, 3, 23),
+        (ModuleStoreEnum.Type.mongo, 1, _recalc_expected_query_counts()),
+        (ModuleStoreEnum.Type.split, 3, _recalc_expected_query_counts()),
     )
     @ddt.unpack
     def test_query_counts_dont_change_with_more_content(self, default_store, num_mongo_calls, num_sql_calls):
@@ -240,8 +263,8 @@ class RecalculateSubsectionGradeTest(HasCourseWithProblemsMixin, ModuleStoreTest
             self.assertEqual(len(PersistentSubsectionGrade.bulk_read_grades(self.user.id, self.course.id)), 0)
 
     @ddt.data(
-        (ModuleStoreEnum.Type.mongo, 1, 24),
-        (ModuleStoreEnum.Type.split, 3, 24),
+        (ModuleStoreEnum.Type.mongo, 1, _recalc_persistent_expected_query_counts()),
+        (ModuleStoreEnum.Type.split, 3, _recalc_persistent_expected_query_counts()),
     )
     @ddt.unpack
     def test_persistent_grades_enabled_on_course(self, default_store, num_mongo_queries, num_sql_queries):
diff --git a/lms/djangoapps/instructor_analytics/tests/test_basic.py b/lms/djangoapps/instructor_analytics/tests/test_basic.py
index 45cecd69af..125cd68748 100644
--- a/lms/djangoapps/instructor_analytics/tests/test_basic.py
+++ b/lms/djangoapps/instructor_analytics/tests/test_basic.py
@@ -536,10 +536,7 @@ class TestCourseRegistrationCodeAnalyticsBasic(ModuleStoreTestCase):
         CourseSalesAdminRole(self.course.id).add_users(self.instructor)
 
         # Create a paid course mode.
-        mode = CourseModeFactory.create()
-        mode.course_id = self.course.id
-        mode.min_price = 1
-        mode.save()
+        mode = CourseModeFactory.create(course_id=self.course.id, min_price=1)
 
         url = reverse('generate_registration_codes',
                       kwargs={'course_id': text_type(self.course.id)})
diff --git a/lms/djangoapps/lti_provider/tests/test_views.py b/lms/djangoapps/lti_provider/tests/test_views.py
index 482dc866f6..a2b9ae92bc 100644
--- a/lms/djangoapps/lti_provider/tests/test_views.py
+++ b/lms/djangoapps/lti_provider/tests/test_views.py
@@ -45,14 +45,18 @@ COURSE_PARAMS = {
 ALL_PARAMS = dict(LTI_DEFAULT_PARAMS.items() + COURSE_PARAMS.items())
 
 
-def build_launch_request():
+def build_launch_request(extra_post_data=None, param_to_delete=None):
     """
     Helper method to create a new request object for the LTI launch.
     """
-    request = RequestFactory().post('/')
+    if extra_post_data is None:
+        extra_post_data = {}
+    post_data = dict(LTI_DEFAULT_PARAMS.items() + extra_post_data.items())
+    if param_to_delete:
+        del post_data[param_to_delete]
+    request = RequestFactory().post('/', data=post_data)
     request.user = UserFactory.create()
     request.session = {}
-    request.POST.update(LTI_DEFAULT_PARAMS)
     return request
 
 
@@ -110,8 +114,7 @@ class LtiLaunchTest(LtiTestMixin, TestCase):
         """
         Helper method to remove a parameter from the LTI launch and call the view
         """
-        request = build_launch_request()
-        del request.POST[missing_param]
+        request = build_launch_request(param_to_delete=missing_param)
         return views.lti_launch(request, None, None)
 
     def test_launch_with_missing_parameters(self):
@@ -152,8 +155,7 @@ class LtiLaunchTest(LtiTestMixin, TestCase):
     def test_lti_consumer_record_supplemented_with_guid(self, _render):
         self.mock_verify.return_value = False
 
-        request = build_launch_request()
-        request.POST.update(LTI_OPTIONAL_PARAMS)
+        request = build_launch_request(LTI_OPTIONAL_PARAMS)
         with self.assertNumQueries(3):
             views.lti_launch(request, None, None)
         consumer = models.LtiConsumer.objects.get(
diff --git a/lms/djangoapps/support/tests/test_refund.py b/lms/djangoapps/support/tests/test_refund.py
index dfe5508b7e..d2db69eb41 100644
--- a/lms/djangoapps/support/tests/test_refund.py
+++ b/lms/djangoapps/support/tests/test_refund.py
@@ -87,7 +87,7 @@ class RefundTests(ModuleStoreTestCase):
 
     def test_bad_courseid(self):
         response = self.client.post('/support/refund/', {'course_id': 'foo', 'user': self.student.email})
-        self.assertContains(response, 'Invalid course id')
+        self.assertContains(response, 'Course id invalid')
 
     def test_bad_user(self):
         response = self.client.post('/support/refund/', {'course_id': str(self.course_id), 'user': 'unknown@foo.com'})
diff --git a/lms/djangoapps/support/views/refund.py b/lms/djangoapps/support/views/refund.py
index 7448f17981..e88a851608 100644
--- a/lms/djangoapps/support/views/refund.py
+++ b/lms/djangoapps/support/views/refund.py
@@ -22,6 +22,7 @@ from django.views.generic.edit import FormView
 from opaque_keys import InvalidKeyError
 from opaque_keys.edx.keys import CourseKey
 
+from openedx.core.lib.courses import clean_course_id
 from student.models import CourseEnrollment
 from support.decorators import require_support_permission
 
@@ -49,17 +50,9 @@ class RefundForm(forms.Form):
 
     def clean_course_id(self):
         """
-        validate course id field
+        Validate the course id
         """
-        course_id = self.cleaned_data['course_id']
-        try:
-            course_key = CourseKey.from_string(course_id)
-        except InvalidKeyError:
-            try:
-                course_key = CourseKey.from_string(course_id)
-            except InvalidKeyError:
-                raise forms.ValidationError(_("Invalid course id"))
-        return course_key
+        return clean_course_id(self)
 
     def clean(self):
         """
diff --git a/lms/envs/common.py b/lms/envs/common.py
index 05c2bd52ba..3515fd855c 100644
--- a/lms/envs/common.py
+++ b/lms/envs/common.py
@@ -668,8 +668,7 @@ derived_collection_entry('DEFAULT_TEMPLATE_ENGINE', 'DIRS')
 
 ###############################################################################################
 
-# use the ratelimit backend to prevent brute force attacks
-AUTHENTICATION_BACKENDS = ['ratelimitbackend.backends.RateLimitModelBackend']
+AUTHENTICATION_BACKENDS = ['openedx.core.djangoapps.oauth_dispatch.dot_overrides.validators.EdxRateLimitedAllowAllUsersModelBackend']
 STUDENT_FILEUPLOAD_MAX_SIZE = 4 * 1000 * 1000  # 4 MB
 MAX_FILEUPLOADS_PER_INPUT = 20
 
diff --git a/openedx/core/djangoapps/cors_csrf/authentication.py b/openedx/core/djangoapps/cors_csrf/authentication.py
index 55bffe33cb..91dc5098a2 100644
--- a/openedx/core/djangoapps/cors_csrf/authentication.py
+++ b/openedx/core/djangoapps/cors_csrf/authentication.py
@@ -1,7 +1,8 @@
 """
 Django Rest Framework Authentication classes for cross-domain end-points.
 """
-
+import django
+from django.middleware.csrf import CsrfViewMiddleware
 from rest_framework import authentication
 
 from .helpers import is_cross_domain_request_allowed, skip_cross_domain_referer_check
@@ -23,6 +24,12 @@ class SessionAuthenticationCrossDomainCsrf(authentication.SessionAuthentication)
     Since this subclass overrides only the `enforce_csrf()` method,
     it can be mixed in with other `SessionAuthentication` subclasses.
     """
+    # TODO: Remove Django 1.11 upgrade shim
+    # SHIM: Call new process_request in Django 1.11 to process CSRF token in cookie.
+    def _process_enforce_csrf(self, request):
+        if django.VERSION >= (1, 11):
+            CsrfViewMiddleware().process_request(request)
+        return super(SessionAuthenticationCrossDomainCsrf, self).enforce_csrf(request)
 
     def enforce_csrf(self, request):
         """
@@ -30,6 +37,6 @@ class SessionAuthenticationCrossDomainCsrf(authentication.SessionAuthentication)
         """
         if is_cross_domain_request_allowed(request):
             with skip_cross_domain_referer_check(request):
-                return super(SessionAuthenticationCrossDomainCsrf, self).enforce_csrf(request)
+                return self._process_enforce_csrf(request)
         else:
-            return super(SessionAuthenticationCrossDomainCsrf, self).enforce_csrf(request)
+            return self._process_enforce_csrf(request)
diff --git a/openedx/core/djangoapps/external_auth/tests/test_shib.py b/openedx/core/djangoapps/external_auth/tests/test_shib.py
index c5baf55f57..fc6b79f3bc 100644
--- a/openedx/core/djangoapps/external_auth/tests/test_shib.py
+++ b/openedx/core/djangoapps/external_auth/tests/test_shib.py
@@ -526,10 +526,10 @@ class ShibSPTestModifiedCourseware(ModuleStoreTestCase):
         # Tests the two case for courses, limited and not
         for course in [shib_course, open_enroll_course]:
             for student in [shib_student, other_ext_student, int_student]:
-                request = self.request_factory.post('/change_enrollment')
-
-                request.POST.update({'enrollment_action': 'enroll',
-                                     'course_id': text_type(course.id)})
+                request = self.request_factory.post(
+                    '/change_enrollment',
+                    data={'enrollment_action': 'enroll', 'course_id': text_type(course.id)}
+                )
                 request.user = student
                 response = change_enrollment(request)
                 # If course is not limited or student has correct shib extauth then enrollment should be allowed
diff --git a/openedx/core/djangoapps/oauth_dispatch/dot_overrides/validators.py b/openedx/core/djangoapps/oauth_dispatch/dot_overrides/validators.py
index 702d0b4e06..978e8394af 100644
--- a/openedx/core/djangoapps/oauth_dispatch/dot_overrides/validators.py
+++ b/openedx/core/djangoapps/oauth_dispatch/dot_overrides/validators.py
@@ -5,12 +5,14 @@ from __future__ import unicode_literals
 
 from datetime import datetime
 
+import django
 from django.contrib.auth import authenticate, get_user_model
 from django.db.models.signals import pre_save
 from django.dispatch import receiver
 from oauth2_provider.models import AccessToken
 from oauth2_provider.oauth2_validators import OAuth2Validator
 from pytz import utc
+from ratelimitbackend.backends import RateLimitMixin
 
 from ..models import RestrictedApplication
 
@@ -29,6 +31,30 @@ def on_access_token_presave(sender, instance, *args, **kwargs):  # pylint: disab
         RestrictedApplication.set_access_token_as_expired(instance)
 
 
+# TODO: Remove Django 1.11 upgrade shim
+# SHIM: Allow users that are inactive to still authenticate while keeping rate-limiting functionality.
+if django.VERSION < (1, 10):
+    # Old backend which allowed inactive users to authenticate prior to Django 1.10.
+    from django.contrib.auth.backends import ModelBackend as UserModelBackend
+else:
+    # Django 1.10+ ModelBackend disallows inactive users from authenticating, so instead we use
+    # AllowAllUsersModelBackend which is the closest alternative.
+    from django.contrib.auth.backends import AllowAllUsersModelBackend as UserModelBackend
+
+
+class EdxRateLimitedAllowAllUsersModelBackend(RateLimitMixin, UserModelBackend):
+    """
+    Authentication backend needed to incorporate rate limiting of login attempts - but also
+    enabling users with is_active of False in the Django auth_user model to still authenticate.
+    This is necessary for mobile users using 3rd party auth who have not activated their accounts,
+    Inactive users who use 1st party auth (username/password auth) will still fail login attempts,
+    just at a higher layer, in the login_user view.
+
+    See: https://openedx.atlassian.net/browse/TNL-4516
+    """
+    pass
+
+
 class EdxOAuth2Validator(OAuth2Validator):
     """
     Validator class that implements edX-specific custom behavior:
diff --git a/openedx/core/djangoapps/video_config/forms.py b/openedx/core/djangoapps/video_config/forms.py
index 45fb6ad54c..e5b13d2f84 100644
--- a/openedx/core/djangoapps/video_config/forms.py
+++ b/openedx/core/djangoapps/video_config/forms.py
@@ -11,6 +11,7 @@ from openedx.core.djangoapps.video_config.models import (
     CourseHLSPlaybackEnabledFlag,
     CourseVideoTranscriptEnabledFlag,
 )
+from openedx.core.lib.courses import clean_course_id
 from xmodule.modulestore.django import modulestore
 
 log = logging.getLogger(__name__)
@@ -29,22 +30,7 @@ class CourseSpecificFlagAdminBaseForm(forms.ModelForm):
         """
         Validate the course id
         """
-        cleaned_id = self.cleaned_data["course_id"]
-        try:
-            course_key = CourseLocator.from_string(cleaned_id)
-        except InvalidKeyError:
-            msg = u'Course id invalid. Entered course id was: "{course_id}."'.format(
-                course_id=cleaned_id
-            )
-            raise forms.ValidationError(msg)
-
-        if not modulestore().has_course(course_key):
-            msg = u'Course not found. Entered course id was: "{course_key}". '.format(
-                course_key=unicode(course_key)
-            )
-            raise forms.ValidationError(msg)
-
-        return course_key
+        return clean_course_id(self)
 
 
 class CourseHLSPlaybackFlagAdminForm(CourseSpecificFlagAdminBaseForm):
diff --git a/openedx/core/lib/api/tests/test_authentication.py b/openedx/core/lib/api/tests/test_authentication.py
index 6a28112814..9e0475805d 100644
--- a/openedx/core/lib/api/tests/test_authentication.py
+++ b/openedx/core/lib/api/tests/test_authentication.py
@@ -40,13 +40,13 @@ factory = APIRequestFactory()  # pylint: disable=invalid-name
 class MockView(APIView):  # pylint: disable=missing-docstring
     permission_classes = (IsAuthenticated,)
 
-    def get(self, request):  # pylint: disable=missing-docstring,unused-argument
+    def get(self, request):  # pylint: disable=unused-argument
         return HttpResponse({'a': 1, 'b': 2, 'c': 3})
 
-    def post(self, request):  # pylint: disable=missing-docstring,unused-argument
+    def post(self, request):  # pylint: disable=unused-argument
         return HttpResponse({'a': 1, 'b': 2, 'c': 3})
 
-    def put(self, request):  # pylint: disable=missing-docstring,unused-argument
+    def put(self, request):  # pylint: disable=unused-argument
         return HttpResponse({'a': 1, 'b': 2, 'c': 3})
 
 
diff --git a/openedx/core/lib/courses.py b/openedx/core/lib/courses.py
index 5688ff7ae0..929a4ed815 100644
--- a/openedx/core/lib/courses.py
+++ b/openedx/core/lib/courses.py
@@ -63,7 +63,7 @@ def clean_course_id(model_form, is_required=True):
     Returns:
         (CourseKey) The cleaned and validated course_id as a CourseKey.
 
-    NOTE: This should ultimately replace all copies of "def clean_course_id".
+    NOTE: Use this method in model forms instead of a custom "clean_course_id" method!
 
     """
     cleaned_id = model_form.cleaned_data["course_id"]
@@ -74,11 +74,11 @@ def clean_course_id(model_form, is_required=True):
     try:
         course_key = CourseKey.from_string(cleaned_id)
     except InvalidKeyError:
-        msg = u'Course id invalid. Entered course id was: "{0}."'.format(cleaned_id)
+        msg = u'Course id invalid. Entered course id was: "{0}".'.format(cleaned_id)
         raise forms.ValidationError(msg)
 
     if not modulestore().has_course(course_key):
-        msg = u'Course not found. Entered course id was: "{0}". '.format(text_type(course_key))
+        msg = u'Course not found. Entered course id was: "{0}".'.format(text_type(course_key))
         raise forms.ValidationError(msg)
 
     return course_key
diff --git a/openedx/features/course_experience/__init__.py b/openedx/features/course_experience/__init__.py
index b544d264bd..a2dff74d45 100644
--- a/openedx/features/course_experience/__init__.py
+++ b/openedx/features/course_experience/__init__.py
@@ -86,8 +86,8 @@ class CourseHomeMessages(UserMessageCollection):
     NAMESPACE = 'course_home_level_messages'
 
     @classmethod
-    def get_namespace(self):
+    def get_namespace(cls):
         """
         Returns the namespace of the message collection.
         """
-        return self.NAMESPACE
+        return cls.NAMESPACE
diff --git a/openedx/features/course_experience/plugins.py b/openedx/features/course_experience/plugins.py
index a47cf7eb4d..50613f9b5e 100644
--- a/openedx/features/course_experience/plugins.py
+++ b/openedx/features/course_experience/plugins.py
@@ -6,13 +6,13 @@ This includes any locally defined CourseTools.
 from django.core.urlresolvers import reverse
 from django.utils.translation import ugettext as _
 
-from course_tools import CourseTool
 from courseware.courses import get_course_by_id
 from student.models import CourseEnrollment
-from views.course_reviews import CourseReviewsModuleFragmentView
-from views.course_updates import CourseUpdatesFragmentView
 
 from . import SHOW_REVIEWS_TOOL_FLAG, UNIFIED_COURSE_TAB_FLAG
+from .course_tools import CourseTool
+from .views.course_reviews import CourseReviewsModuleFragmentView
+from .views.course_updates import CourseUpdatesFragmentView
 
 
 class CourseUpdatesTool(CourseTool):
diff --git a/openedx/features/course_experience/tests/views/test_course_outline.py b/openedx/features/course_experience/tests/views/test_course_outline.py
index 360034deb1..14e25b25ff 100644
--- a/openedx/features/course_experience/tests/views/test_course_outline.py
+++ b/openedx/features/course_experience/tests/views/test_course_outline.py
@@ -36,7 +36,6 @@ class TestCourseOutlinePage(SharedModuleStoreTestCase):
         Set up an array of various courses to be tested.
         """
         # setUpClassAndTestData() already calls setUpClass on SharedModuleStoreTestCase
-        # pylint: disable=super-method-not-called
         with super(TestCourseOutlinePage, cls).setUpClassAndTestData():
             cls.courses = []
             course = CourseFactory.create()
@@ -261,7 +260,6 @@ class TestCourseOutlineResumeCourse(SharedModuleStoreTestCase):
         Creates a test course that can be used for non-destructive tests
         """
         # setUpClassAndTestData() already calls setUpClass on SharedModuleStoreTestCase
-        # pylint: disable=super-method-not-called
         with super(TestCourseOutlineResumeCourse, cls).setUpClassAndTestData():
             cls.course = cls.create_test_course()
 
@@ -369,7 +367,7 @@ class TestCourseOutlineResumeCourse(SharedModuleStoreTestCase):
 
         # remove one of the sequentials from the chapter
         with self.store.branch_setting(ModuleStoreEnum.Branch.draft_preferred, course.id):
-            self.store.delete_item(sequential.location, self.user.id)  # pylint: disable=no-member
+            self.store.delete_item(sequential.location, self.user.id)
 
         # check resume course buttons
         response = self.client.get(course_home_url(course))
@@ -398,7 +396,7 @@ class TestCourseOutlineResumeCourse(SharedModuleStoreTestCase):
         # remove all sequentials from chapter
         with self.store.branch_setting(ModuleStoreEnum.Branch.draft_preferred, course.id):
             for sequential in chapter.children:
-                self.store.delete_item(sequential.location, self.user.id)  # pylint: disable=no-member
+                self.store.delete_item(sequential.location, self.user.id)
 
         # check resume course buttons
         response = self.client.get(course_home_url(course))
diff --git a/openedx/features/course_experience/urls.py b/openedx/features/course_experience/urls.py
index c9e8be4130..002d66b4af 100644
--- a/openedx/features/course_experience/urls.py
+++ b/openedx/features/course_experience/urls.py
@@ -4,14 +4,14 @@ Defines URLs for the course experience.
 
 from django.conf.urls import url
 
-from views.course_dates import CourseDatesFragmentMobileView
-from views.course_home import CourseHomeFragmentView, CourseHomeView
-from views.course_outline import CourseOutlineFragmentView
-from views.course_reviews import CourseReviewsView
-from views.course_updates import CourseUpdatesFragmentView, CourseUpdatesView
-from views.course_sock import CourseSockFragmentView
-from views.latest_update import LatestUpdateFragmentView
-from views.welcome_message import WelcomeMessageFragmentView, dismiss_welcome_message
+from .views.course_dates import CourseDatesFragmentMobileView
+from .views.course_home import CourseHomeFragmentView, CourseHomeView
+from .views.course_outline import CourseOutlineFragmentView
+from .views.course_reviews import CourseReviewsView
+from .views.course_updates import CourseUpdatesFragmentView, CourseUpdatesView
+from .views.course_sock import CourseSockFragmentView
+from .views.latest_update import LatestUpdateFragmentView
+from .views.welcome_message import WelcomeMessageFragmentView, dismiss_welcome_message
 
 urlpatterns = [
     url(
diff --git a/openedx/features/course_experience/views/course_home_messages.py b/openedx/features/course_experience/views/course_home_messages.py
index a80c45429b..5dc49afd1d 100644
--- a/openedx/features/course_experience/views/course_home_messages.py
+++ b/openedx/features/course_experience/views/course_home_messages.py
@@ -8,15 +8,20 @@ from babel.dates import format_date, format_timedelta
 from django.contrib import auth
 from django.template.loader import render_to_string
 from django.utils.http import urlquote_plus
-from pytz import UTC
-from django.utils.translation import get_language, to_locale
 from django.utils.translation import ugettext as _
 from django.utils.translation import get_language, to_locale
 from opaque_keys.edx.keys import CourseKey
+from pytz import UTC
 from web_fragments.fragment import Fragment
 
 from courseware.courses import get_course_date_blocks, get_course_with_access
-from lms.djangoapps.course_goals.api import get_course_goal, get_course_goal_options, valid_course_goals_ordered, get_goal_api_url, has_course_goal_permission
+from lms.djangoapps.course_goals.api import (
+    get_course_goal,
+    get_course_goal_options,
+    get_goal_api_url,
+    has_course_goal_permission,
+    valid_course_goals_ordered
+)
 from lms.djangoapps.course_goals.models import GOAL_KEY_CHOICES
 from openedx.core.djangoapps.plugin_api.views import EdxFragmentView
 from openedx.core.djangolib.markup import HTML, Text
@@ -52,7 +57,9 @@ class CourseHomeMessageFragmentView(EdxFragmentView):
         # Get time until the start date, if already started, or no start date, value will be zero or negative
         now = datetime.now(UTC)
         already_started = course.start and now > course.start
-        days_until_start_string = "started" if already_started else format_timedelta(course.start - now, locale=to_locale(get_language()))
+        days_until_start_string = "started" if already_started else format_timedelta(
+            course.start - now, locale=to_locale(get_language())
+        )
         course_start_data = {
             'course_start_date': format_date(course.start, locale=to_locale(get_language())),
             'already_started': already_started,