diff --git a/cms/djangoapps/contentstore/views/course.py b/cms/djangoapps/contentstore/views/course.py
index 7bad397cba..6b2e40bde1 100644
--- a/cms/djangoapps/contentstore/views/course.py
+++ b/cms/djangoapps/contentstore/views/course.py
@@ -72,7 +72,7 @@ from common.djangoapps.util.string_utils import _has_non_ascii_characters
 from common.djangoapps.xblock_django.api import deprecated_xblocks
 from xmodule.contentstore.content import StaticContent
 from xmodule.course_module import DEFAULT_START_DATE, CourseFields
-from xmodule.error_module import ErrorDescriptor
+from xmodule.error_module import ErrorBlock
 from xmodule.modulestore import EdxJSONEncoder
 from xmodule.modulestore.django import modulestore
 from xmodule.modulestore.exceptions import DuplicateCourseError, ItemNotFoundError
@@ -412,7 +412,7 @@ def _accessible_courses_iter(request):
         """
         Filter out unusable and inaccessible courses
         """
-        if isinstance(course, ErrorDescriptor):
+        if isinstance(course, ErrorBlock):
             return False
 
         # Custom Courses for edX (CCX) is an edX feature for re-using course content.
@@ -499,7 +499,7 @@ def _accessible_libraries_iter(user, org=None):
         libraries = [] if org == '' else modulestore().get_libraries(org=org)
     else:
         libraries = modulestore().get_library_summaries()
-    # No need to worry about ErrorDescriptors - split's get_libraries() never returns them.
+    # No need to worry about ErrorBlocks - split's get_libraries() never returns them.
     return (lib for lib in libraries if has_studio_read_access(user, lib.location.library_key))
 
 
@@ -751,7 +751,7 @@ def _process_courses_list(courses_iter, in_process_course_actions, split_archive
     archived_courses = []
 
     for course in courses_iter:
-        if isinstance(course, ErrorDescriptor) or (course.id in in_process_action_course_keys):
+        if isinstance(course, ErrorBlock) or (course.id in in_process_action_course_keys):
             continue
 
         formatted_course = format_course_for_view(course)
diff --git a/cms/djangoapps/contentstore/views/preview.py b/cms/djangoapps/contentstore/views/preview.py
index 81b1f813da..fde3acbdc0 100644
--- a/cms/djangoapps/contentstore/views/preview.py
+++ b/cms/djangoapps/contentstore/views/preview.py
@@ -32,7 +32,7 @@ from openedx.core.lib.xblock_utils import (
 )
 from common.djangoapps.xblock_django.user_service import DjangoXBlockUserService
 from xmodule.contentstore.django import contentstore
-from xmodule.error_module import ErrorDescriptor
+from xmodule.error_module import ErrorBlock
 from xmodule.exceptions import NotFoundError, ProcessingError
 from xmodule.modulestore.django import ModuleI18nService, modulestore
 from xmodule.partitions.partitions_service import PartitionService
@@ -209,7 +209,7 @@ def _preview_module_system(request, descriptor, field_data):
         # Set up functions to modify the fragment produced by student_view
         wrappers=wrappers,
         wrappers_asides=wrappers_asides,
-        error_descriptor_class=ErrorDescriptor,
+        error_descriptor_class=ErrorBlock,
         get_user_role=lambda: get_user_role(request.user, course_id),
         # Get the raw DescriptorSystem, not the CombinedSystem
         descriptor_runtime=descriptor._runtime,  # pylint: disable=protected-access
diff --git a/common/djangoapps/student/tests/test_course_listing.py b/common/djangoapps/student/tests/test_course_listing.py
index 00edc920ee..ac40dc500d 100644
--- a/common/djangoapps/student/tests/test_course_listing.py
+++ b/common/djangoapps/student/tests/test_course_listing.py
@@ -18,7 +18,7 @@ from common.djangoapps.student.roles import GlobalStaff
 from common.djangoapps.student.tests.factories import UserFactory
 from common.djangoapps.student.views import get_course_enrollments
 from common.djangoapps.util.milestones_helpers import get_pre_requisite_courses_not_completed, set_prerequisite_courses
-from xmodule.error_module import ErrorDescriptor
+from xmodule.error_module import ErrorBlock
 from xmodule.modulestore import ModuleStoreEnum
 from xmodule.modulestore.django import modulestore
 from xmodule.modulestore.tests.django_utils import ModuleStoreTestCase
@@ -104,7 +104,7 @@ class TestCourseListing(ModuleStoreTestCase, MilestonesTestCaseMixin):
 
     def test_errored_course_regular_access(self):
         """
-        Test the course list for regular staff when get_course returns an ErrorDescriptor
+        Test the course list for regular staff when get_course returns an ErrorBlock
         """
         # pylint: disable=protected-access
         mongo_store = modulestore()._get_modulestore_by_type(ModuleStoreEnum.Type.mongo)
@@ -112,7 +112,7 @@ class TestCourseListing(ModuleStoreTestCase, MilestonesTestCaseMixin):
         self._create_course_with_access_groups(course_key, default_store=ModuleStoreEnum.Type.mongo)
 
         with mock.patch('xmodule.modulestore.mongo.base.MongoKeyValueStore', mock.Mock(side_effect=Exception)):
-            self.assertIsInstance(modulestore().get_course(course_key), ErrorDescriptor)
+            self.assertIsInstance(modulestore().get_course(course_key), ErrorBlock)
 
             # Invalidate (e.g., delete) the corresponding CourseOverview, forcing get_course to be called.
             CourseOverview.objects.filter(id=course_key).delete()
diff --git a/common/lib/xmodule/setup.py b/common/lib/xmodule/setup.py
index 09d193d049..75ca6b9521 100644
--- a/common/lib/xmodule/setup.py
+++ b/common/lib/xmodule/setup.py
@@ -9,8 +9,6 @@ XMODULES = [
     "customtag = xmodule.template_module:CustomTagDescriptor",
     "discuss = xmodule.backcompat_module:TranslateCustomTagDescriptor",
     "image = xmodule.backcompat_module:TranslateCustomTagDescriptor",
-    "error = xmodule.error_module:ErrorDescriptor",
-    "nonstaff_error = xmodule.error_module:NonStaffErrorDescriptor",
     "poll_question = xmodule.poll_module:PollDescriptor",
     "problemset = xmodule.seq_module:SequenceDescriptor",
     "section = xmodule.backcompat_module:SemanticSectionDescriptor",
@@ -28,10 +26,12 @@ XBLOCKS = [
     "annotatable = xmodule.annotatable_module:AnnotatableBlock",
     "conditional = xmodule.conditional_module:ConditionalBlock",
     "course_info = xmodule.html_module:CourseInfoBlock",
+    "error = xmodule.error_module:ErrorBlock",
     "html = xmodule.html_module:HtmlBlock",
     "library = xmodule.library_root_xblock:LibraryRoot",
     "library_content = xmodule.library_content_module:LibraryContentBlock",
     "library_sourced = xmodule.library_sourced_block:LibrarySourcedBlock",
+    "nonstaff_error = xmodule.error_module:NonStaffErrorBlock",
     "problem = xmodule.capa_module:ProblemBlock",
     "randomize = xmodule.randomize_module:RandomizeBlock",
     "split_test = xmodule.split_test_module:SplitTestBlock",
diff --git a/common/lib/xmodule/xmodule/conditional_module.py b/common/lib/xmodule/xmodule/conditional_module.py
index fb01733930..1b842d5455 100644
--- a/common/lib/xmodule/xmodule/conditional_module.py
+++ b/common/lib/xmodule/xmodule/conditional_module.py
@@ -216,7 +216,7 @@ class ConditionalBlock(
                 if not hasattr(module, attr_name):
                     # We don't throw an exception here because it is possible for
                     # the descriptor of a required module to have a property but
-                    # for the resulting module to be a (flavor of) ErrorModule.
+                    # for the resulting module to be a (flavor of) ErrorBlock.
                     # So just log and return false.
                     if module is not None:
                         # We do not want to log when module is None, and it is when requester
diff --git a/common/lib/xmodule/xmodule/error_module.py b/common/lib/xmodule/xmodule/error_module.py
index 604ba71f7d..a6b52aa5eb 100644
--- a/common/lib/xmodule/xmodule/error_module.py
+++ b/common/lib/xmodule/xmodule/error_module.py
@@ -11,18 +11,25 @@ import sys
 
 import six
 from lxml import etree
+from web_fragments.fragment import Fragment
 from xblock.field_data import DictFieldData
 from xblock.fields import Scope, ScopeIds, String
 
 from xmodule.errortracker import exc_info_to_str
 from xmodule.modulestore import EdxJSONEncoder
-from xmodule.x_module import XModule, XModuleDescriptor
+from xmodule.x_module import (
+    HTMLSnippet,
+    ResourceTemplates,
+    XModuleMixin,
+    XModuleDescriptorToXBlockMixin,
+    XModuleToXBlockMixin,
+)
 
 log = logging.getLogger(__name__)
 
 # NOTE: This is not the most beautiful design in the world, but there's no good
 # way to tell if the module is being used in a staff context or not.  Errors that get discovered
-# at course load time are turned into ErrorDescriptor objects, and automatically hidden from students.
+# at course load time are turned into ErrorBlock objects, and automatically hidden from students.
 # Unfortunately, we can also have errors when loading modules mid-request, and then we need to decide
 # what to show, and the logic for that belongs in the LMS (e.g. in get_module), so the error handler
 # decides whether to create a staff or not-staff module.
@@ -30,62 +37,49 @@ log = logging.getLogger(__name__)
 
 class ErrorFields(object):
     """
-    XBlock fields used by the ErrorModules
+    XBlock fields used by the ErrorBlocks
     """
     contents = String(scope=Scope.content)
     error_msg = String(scope=Scope.content)
     display_name = String(scope=Scope.settings)
 
 
-class ErrorModule(ErrorFields, XModule):
+class ErrorBlock(
+    ErrorFields,
+    XModuleDescriptorToXBlockMixin,
+    XModuleToXBlockMixin,
+    HTMLSnippet,
+    ResourceTemplates,
+    XModuleMixin,
+):  # pylint: disable=abstract-method
     """
     Module that gets shown to staff when there has been an error while
     loading or rendering other modules
     """
 
-    def get_html(self):
-        '''Show an error to staff.
-        TODO (vshnayder): proper style, divs, etc.
-        '''
-        # staff get to see all the details
-        return self.system.render_template('module-error.html', {
+    resources_dir = None
+
+    def student_view(self, _context):
+        """
+        Return a fragment that contains the html for the student view.
+        """
+        fragment = Fragment(self.system.render_template('module-error.html', {
             'staff_access': True,
             'data': self.contents,
             'error': self.error_msg,
-        })
+        }))
+        return fragment
 
-
-class NonStaffErrorModule(ErrorFields, XModule):
-    """
-    Module that gets shown to students when there has been an error while
-    loading or rendering other modules
-    """
-    def get_html(self):
-        '''Show an error to a student.
-        TODO (vshnayder): proper style, divs, etc.
-        '''
-        # staff get to see all the details
-        return self.system.render_template('module-error.html', {
-            'staff_access': False,
-            'data': "",
-            'error': "",
-        })
-
-
-class ErrorDescriptor(ErrorFields, XModuleDescriptor):
-    """
-    Module that provides a raw editing view of broken xml.
-    """
-    module_class = ErrorModule
-    resources_dir = None
-
-    def get_html(self):
-        return u''
+    def studio_view(self, _context):
+        """
+        Show empty edit view since this is not editable.
+        """
+        return Fragment('')
 
     @classmethod
     def _construct(cls, system, contents, error_msg, location, for_parent=None):
         """
-        Build a new ErrorDescriptor. using ``system``.
+        Build a new ErrorBlock using ``system``.
 
         Arguments:
             system (:class:`DescriptorSystem`): The :class:`DescriptorSystem` used
@@ -106,7 +100,7 @@ class ErrorDescriptor(ErrorFields, XModuleDescriptor):
                 # Pick a unique url_name -- the sha1 hash of the contents.
                 # NOTE: We could try to pull out the url_name of the errored descriptor,
                 # but url_names aren't guaranteed to be unique between descriptor types,
-                # and ErrorDescriptor can wrap any type.  When the wrapped module is fixed,
+                # and ErrorBlock can wrap any type.  When the wrapped module is fixed,
                 # it will be written out with the original url_name.
                 name=hashlib.sha1(contents.encode('utf8')).hexdigest()
             )
@@ -207,8 +201,18 @@ class ErrorDescriptor(ErrorFields, XModuleDescriptor):
             return etree.tostring(root, encoding='unicode')
 
 
-class NonStaffErrorDescriptor(ErrorDescriptor):
+class NonStaffErrorBlock(ErrorBlock):  # pylint: disable=abstract-method
     """
-    Module that provides non-staff error messages.
+    Block that gets shown to students when there has been an error while
+    loading or rendering other blocks.
     """
-    module_class = NonStaffErrorModule
+    def student_view(self, _context):
+        """
+        Return a fragment that contains the html for the student view.
+        """
+        fragment = Fragment(self.system.render_template('module-error.html', {
+            'staff_access': False,
+            'data': '',
+            'error': '',
+        }))
+        return fragment
diff --git a/common/lib/xmodule/xmodule/modulestore/mongo/base.py b/common/lib/xmodule/xmodule/modulestore/mongo/base.py
index 2aedf6f1e6..ded0ad545f 100644
--- a/common/lib/xmodule/xmodule/modulestore/mongo/base.py
+++ b/common/lib/xmodule/xmodule/modulestore/mongo/base.py
@@ -38,7 +38,7 @@ from xblock.runtime import KvsFieldData
 
 from xmodule.assetstore import AssetMetadata, CourseAssetsFromStorage
 from xmodule.course_module import CourseSummary
-from xmodule.error_module import ErrorDescriptor
+from xmodule.error_module import ErrorBlock
 from xmodule.errortracker import exc_info_to_str, null_error_tracker
 from xmodule.exceptions import HeartbeatFailure
 from xmodule.mako_module import MakoDescriptorSystem
@@ -330,7 +330,7 @@ class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):
                 return module
             except Exception:                   # pylint: disable=broad-except
                 log.warning("Failed to load descriptor from %s", json_data, exc_info=True)
-                return ErrorDescriptor.from_json(
+                return ErrorBlock.from_json(
                     json_data,
                     self,
                     location,
@@ -1071,7 +1071,7 @@ class MongoModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase, Mongo
             ],
             []
         )
-        return [course for course in base_list if not isinstance(course, ErrorDescriptor)]
+        return [course for course in base_list if not isinstance(course, ErrorBlock)]
 
     @autoretry_read()
     def _find_one(self, location):
diff --git a/common/lib/xmodule/xmodule/modulestore/split_mongo/caching_descriptor_system.py b/common/lib/xmodule/xmodule/modulestore/split_mongo/caching_descriptor_system.py
index e0a06cb082..06a21feb9b 100644
--- a/common/lib/xmodule/xmodule/modulestore/split_mongo/caching_descriptor_system.py
+++ b/common/lib/xmodule/xmodule/modulestore/split_mongo/caching_descriptor_system.py
@@ -12,7 +12,7 @@ from xblock.core import XBlock
 from xblock.fields import ScopeIds
 from xblock.runtime import KeyValueStore, KvsFieldData
 
-from xmodule.error_module import ErrorDescriptor
+from xmodule.error_module import ErrorBlock
 from xmodule.errortracker import exc_info_to_str
 from xmodule.library_tools import LibraryToolsService
 from xmodule.mako_module import MakoDescriptorSystem
@@ -258,7 +258,7 @@ class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):
             )
         except Exception:  # pylint: disable=broad-except
             log.warning("Failed to load descriptor", exc_info=True)
-            return ErrorDescriptor.from_json(
+            return ErrorBlock.from_json(
                 block_data,
                 self,
                 course_entry_override.course_key.make_usage_key(
diff --git a/common/lib/xmodule/xmodule/modulestore/split_mongo/split.py b/common/lib/xmodule/xmodule/modulestore/split_mongo/split.py
index f8321d20b6..455c9568b6 100644
--- a/common/lib/xmodule/xmodule/modulestore/split_mongo/split.py
+++ b/common/lib/xmodule/xmodule/modulestore/split_mongo/split.py
@@ -83,7 +83,7 @@ from xblock.fields import Reference, ReferenceList, ReferenceValueDict, Scope
 
 from xmodule.assetstore import AssetMetadata
 from xmodule.course_module import CourseSummary
-from xmodule.error_module import ErrorDescriptor
+from xmodule.error_module import ErrorBlock
 from xmodule.errortracker import null_error_tracker
 from xmodule.library_content_module import LibrarySummary
 from xmodule.modulestore import (
@@ -988,7 +988,7 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):
             envelope = CourseEnvelope(locator, entry)
             root = entry['root']
             structures_list = self._load_items(envelope, [root], depth=0, **kwargs)
-            if not isinstance(structures_list[0], ErrorDescriptor):
+            if not isinstance(structures_list[0], ErrorBlock):
                 result.append(structures_list[0])
         return result
 
diff --git a/common/lib/xmodule/xmodule/modulestore/xml.py b/common/lib/xmodule/xmodule/modulestore/xml.py
index 60c22ef628..ddf627b89c 100644
--- a/common/lib/xmodule/xmodule/modulestore/xml.py
+++ b/common/lib/xmodule/xmodule/modulestore/xml.py
@@ -27,7 +27,7 @@ from xblock.field_data import DictFieldData
 from xblock.fields import ScopeIds
 from xblock.runtime import DictKeyValueStore
 
-from xmodule.error_module import ErrorDescriptor
+from xmodule.error_module import ErrorBlock
 from xmodule.errortracker import exc_info_to_str, make_error_tracker
 from xmodule.mako_module import MakoDescriptorSystem
 from xmodule.modulestore import COURSE_ROOT, LIBRARY_ROOT, ModuleStoreEnum, ModuleStoreReadBase
@@ -194,7 +194,7 @@ class ImportSystem(XMLParsingSystem, MakoDescriptorSystem):
 
                 self.error_tracker(msg)
                 err_msg = msg + "\n" + exc_info_to_str(sys.exc_info())
-                descriptor = ErrorDescriptor.from_xml(
+                descriptor = ErrorBlock.from_xml(
                     xml,
                     self,
                     id_manager,
@@ -390,7 +390,7 @@ class XMLModuleStore(ModuleStoreReadBase):
 
         if course_descriptor is None:
             pass
-        elif isinstance(course_descriptor, ErrorDescriptor):
+        elif isinstance(course_descriptor, ErrorBlock):
             # Didn't load course.  Instead, save the errors elsewhere.
             self.errored_courses[course_dir] = errorlog
         else:
@@ -529,7 +529,7 @@ class XMLModuleStore(ModuleStoreReadBase):
             )
             course_descriptor = system.process_xml(etree.tostring(course_data, encoding='unicode'))
             # If we fail to load the course, then skip the rest of the loading steps
-            if isinstance(course_descriptor, ErrorDescriptor):
+            if isinstance(course_descriptor, ErrorBlock):
                 return course_descriptor
 
             self.content_importers(system, course_descriptor, course_dir, url_name)
@@ -783,7 +783,7 @@ class XMLModuleStore(ModuleStoreReadBase):
     def get_courses(self, **kwargs):
         """
         Returns a list of course descriptors.  If there were errors on loading,
-        some of these may be ErrorDescriptors instead.
+        some of these may be ErrorBlock instead.
         """
         return list(self.courses.values())
 
diff --git a/common/lib/xmodule/xmodule/tests/__init__.py b/common/lib/xmodule/xmodule/tests/__init__.py
index 9c954d2051..24b6b50bf0 100644
--- a/common/lib/xmodule/xmodule/tests/__init__.py
+++ b/common/lib/xmodule/xmodule/tests/__init__.py
@@ -29,7 +29,7 @@ from xblock.field_data import DictFieldData
 from xblock.fields import Reference, ReferenceList, ReferenceValueDict, ScopeIds
 
 from xmodule.assetstore import AssetMetadata
-from xmodule.error_module import ErrorDescriptor
+from xmodule.error_module import ErrorBlock
 from xmodule.mako_module import MakoDescriptorSystem
 from xmodule.modulestore import ModuleStoreEnum
 from xmodule.modulestore.draft_and_published import ModuleStoreDraftAndPublished
@@ -146,7 +146,7 @@ def get_test_system(
         node_path=os.environ.get("NODE_PATH", "/usr/local/lib/node_modules"),
         anonymous_student_id='student',
         course_id=course_id,
-        error_descriptor_class=ErrorDescriptor,
+        error_descriptor_class=ErrorBlock,
         get_user_role=Mock(name='get_test_system.get_user_role', is_staff=False),
         user_location=Mock(name='get_test_system.user_location'),
         descriptor_runtime=descriptor_system,
diff --git a/common/lib/xmodule/xmodule/tests/test_conditional.py b/common/lib/xmodule/xmodule/tests/test_conditional.py
index 5155a0f787..d2616fc647 100644
--- a/common/lib/xmodule/xmodule/tests/test_conditional.py
+++ b/common/lib/xmodule/xmodule/tests/test_conditional.py
@@ -14,7 +14,7 @@ from xblock.field_data import DictFieldData
 from xblock.fields import ScopeIds
 
 from xmodule.conditional_module import ConditionalBlock
-from xmodule.error_module import NonStaffErrorDescriptor
+from xmodule.error_module import NonStaffErrorBlock
 from xmodule.modulestore.xml import CourseLocationManager, ImportSystem, XMLModuleStore
 from xmodule.tests import DATA_DIR, get_test_descriptor_system, get_test_system
 from xmodule.tests.xml import XModuleXmlImportTest
@@ -63,7 +63,7 @@ class ConditionalFactory(object):
         return a dict of modules: the conditional with a single source and a single child.
         Keys are 'cond_module', 'source_module', and 'child_module'.
 
-        if the source_is_error_module flag is set, create a real ErrorModule for the source.
+        if the source_is_error_module flag is set, create a real ErrorBlock for the source.
         """
         descriptor_system = get_test_descriptor_system()
 
@@ -72,7 +72,7 @@ class ConditionalFactory(object):
                                             "problem", "SampleProblem", deprecated=True)
         if source_is_error_module:
             # Make an error descriptor and module
-            source_descriptor = NonStaffErrorDescriptor.from_xml(
+            source_descriptor = NonStaffErrorBlock.from_xml(
                 'some random xml data',
                 system,
                 id_generator=CourseLocationManager(source_location.course_key),
@@ -192,7 +192,7 @@ class ConditionalBlockBasicTest(unittest.TestCase):
 
     def test_error_as_source(self):
         '''
-        Check that handle_ajax works properly if the source is really an ErrorModule,
+        Check that handle_ajax works properly if the source is really an ErrorBlock,
         and that the condition is not satisfied.
         '''
         modules = ConditionalFactory.create(self.test_system, source_is_error_module=True)
diff --git a/common/lib/xmodule/xmodule/tests/test_error_module.py b/common/lib/xmodule/xmodule/tests/test_error_module.py
index 4a9f751ad1..dce77fcf3f 100644
--- a/common/lib/xmodule/xmodule/tests/test_error_module.py
+++ b/common/lib/xmodule/xmodule/tests/test_error_module.py
@@ -1,5 +1,5 @@
 """
-Tests for ErrorModule and NonStaffErrorModule
+Tests for ErrorBlock and NonStaffErrorBlock
 """
 
 
@@ -12,17 +12,17 @@ from xblock.fields import ScopeIds
 from xblock.runtime import IdReader, Runtime
 from xblock.test.tools import unabc
 
-from xmodule.error_module import ErrorDescriptor, ErrorModule, NonStaffErrorDescriptor
+from xmodule.error_module import ErrorBlock, NonStaffErrorBlock
 from xmodule.modulestore.xml import CourseLocationManager
 from xmodule.tests import get_test_system
 from xmodule.x_module import STUDENT_VIEW, XModule, XModuleDescriptor
 
 
-class SetupTestErrorModules(unittest.TestCase):
-    """Common setUp for use in ErrorModule tests."""
+class SetupTestErrorBlock(unittest.TestCase):
+    """Common setUp for use in ErrorBlock tests."""
 
     def setUp(self):
-        super(SetupTestErrorModules, self).setUp()
+        super().setUp()
         self.system = get_test_system()
         self.course_id = CourseLocator('org', 'course', 'run')
         self.location = self.course_id.make_usage_key('foo', 'bar')
@@ -30,55 +30,55 @@ class SetupTestErrorModules(unittest.TestCase):
         self.error_msg = "Error"
 
 
-class TestErrorModule(SetupTestErrorModules):
+class TestErrorBlock(SetupTestErrorBlock):
     """
-    Tests for ErrorModule and ErrorDescriptor
+    Tests for ErrorBlock
     """
 
-    def test_error_module_xml_rendering(self):
-        descriptor = ErrorDescriptor.from_xml(
+    def test_error_block_xml_rendering(self):
+        descriptor = ErrorBlock.from_xml(
             self.valid_xml,
             self.system,
             CourseLocationManager(self.course_id),
             self.error_msg
         )
-        self.assertIsInstance(descriptor, ErrorDescriptor)
+        self.assertIsInstance(descriptor, ErrorBlock)
         descriptor.xmodule_runtime = self.system
         context_repr = self.system.render(descriptor, STUDENT_VIEW).content
         self.assertIn(self.error_msg, context_repr)
         self.assertIn(repr(self.valid_xml), context_repr)
 
-    def test_error_module_from_descriptor(self):
+    def test_error_block_from_descriptor(self):
         descriptor = MagicMock(
             spec=XModuleDescriptor,
             runtime=self.system,
             location=self.location,
         )
 
-        error_descriptor = ErrorDescriptor.from_descriptor(
+        error_descriptor = ErrorBlock.from_descriptor(
             descriptor, self.error_msg)
-        self.assertIsInstance(error_descriptor, ErrorDescriptor)
+        self.assertIsInstance(error_descriptor, ErrorBlock)
         error_descriptor.xmodule_runtime = self.system
         context_repr = self.system.render(error_descriptor, STUDENT_VIEW).content
         self.assertIn(self.error_msg, context_repr)
         self.assertIn(repr(descriptor), context_repr)
 
 
-class TestNonStaffErrorModule(SetupTestErrorModules):
+class TestNonStaffErrorBlock(SetupTestErrorBlock):
     """
-    Tests for NonStaffErrorModule and NonStaffErrorDescriptor
+    Tests for NonStaffErrorBlock.
     """
 
-    def test_non_staff_error_module_create(self):
-        descriptor = NonStaffErrorDescriptor.from_xml(
+    def test_non_staff_error_block_create(self):
+        descriptor = NonStaffErrorBlock.from_xml(
             self.valid_xml,
             self.system,
             CourseLocationManager(self.course_id)
         )
-        self.assertIsInstance(descriptor, NonStaffErrorDescriptor)
+        self.assertIsInstance(descriptor, NonStaffErrorBlock)
 
     def test_from_xml_render(self):
-        descriptor = NonStaffErrorDescriptor.from_xml(
+        descriptor = NonStaffErrorBlock.from_xml(
             self.valid_xml,
             self.system,
             CourseLocationManager(self.course_id)
@@ -88,16 +88,16 @@ class TestNonStaffErrorModule(SetupTestErrorModules):
         self.assertNotIn(self.error_msg, context_repr)
         self.assertNotIn(repr(self.valid_xml), context_repr)
 
-    def test_error_module_from_descriptor(self):
+    def test_error_block_from_descriptor(self):
         descriptor = MagicMock(
             spec=XModuleDescriptor,
             runtime=self.system,
             location=self.location,
         )
 
-        error_descriptor = NonStaffErrorDescriptor.from_descriptor(
+        error_descriptor = NonStaffErrorBlock.from_descriptor(
             descriptor, self.error_msg)
-        self.assertIsInstance(error_descriptor, ErrorDescriptor)
+        self.assertIsInstance(error_descriptor, ErrorBlock)
         error_descriptor.xmodule_runtime = self.system
         context_repr = self.system.render(error_descriptor, STUDENT_VIEW).content
         self.assertNotIn(self.error_msg, context_repr)
@@ -124,14 +124,14 @@ class TestRuntime(Runtime):
     pass
 
 
-class TestErrorModuleConstruction(unittest.TestCase):
+class TestErrorBlockConstruction(unittest.TestCase):
     """
-    Test that error module construction happens correctly
+    Test that error block construction happens correctly
     """
 
     def setUp(self):
         # pylint: disable=abstract-class-instantiated
-        super(TestErrorModuleConstruction, self).setUp()
+        super().setUp()
         field_data = DictFieldData({})
         self.descriptor = BrokenDescriptor(
             TestRuntime(Mock(spec=IdReader), field_data),
@@ -140,29 +140,29 @@ class TestErrorModuleConstruction(unittest.TestCase):
                      BlockUsageLocator(CourseLocator('org', 'course', 'run'), 'broken', 'name'))
         )
         self.descriptor.xmodule_runtime = TestRuntime(Mock(spec=IdReader), field_data)
-        self.descriptor.xmodule_runtime.error_descriptor_class = ErrorDescriptor
+        self.descriptor.xmodule_runtime.error_descriptor_class = ErrorBlock
         self.descriptor.xmodule_runtime.xmodule_instance = None
 
-    def test_broken_module(self):
+    def test_broken_block(self):
         """
-        Test that when an XModule throws an error during __init__, we
-        get an ErrorModule back from XModuleDescriptor._xmodule
+        Test that when an XModule throws an block during __init__, we
+        get an ErrorBlock back from XModuleDescriptor._xmodule
         """
         module = self.descriptor._xmodule
-        self.assertIsInstance(module, ErrorModule)
+        self.assertIsInstance(module, ErrorBlock)
 
-    @patch.object(ErrorDescriptor, '__init__', Mock(side_effect=TestException))
+    @patch.object(ErrorBlock, '__init__', Mock(side_effect=TestException))
     def test_broken_error_descriptor(self):
         """
-        Test that a broken error descriptor doesn't cause an infinite loop
+        Test that a broken block descriptor doesn't cause an infinite loop
         """
         with self.assertRaises(TestException):
             module = self.descriptor._xmodule
 
-    @patch.object(ErrorModule, '__init__', Mock(side_effect=TestException))
-    def test_broken_error_module(self):
+    @patch.object(ErrorBlock, '__init__', Mock(side_effect=TestException))
+    def test_broken_error_block(self):
         """
-        Test that a broken error module doesn't cause an infinite loop
+        Test that a broken block module doesn't cause an infinite loop
         """
         with self.assertRaises(TestException):
             module = self.descriptor._xmodule
diff --git a/common/lib/xmodule/xmodule/tests/test_import.py b/common/lib/xmodule/xmodule/tests/test_import.py
index 12d08cebac..1b98052398 100644
--- a/common/lib/xmodule/xmodule/tests/test_import.py
+++ b/common/lib/xmodule/xmodule/tests/test_import.py
@@ -122,7 +122,7 @@ class ImportTestCase(BaseCourseTestCase):
     date = Date()
 
     def test_fallback(self):
-        '''Check that malformed xml loads as an ErrorDescriptor.'''
+        '''Check that malformed xml loads as an ErrorBlock.'''
 
         # Use an exotic character to also flush out Unicode issues.
         bad_xml = u'''<sequential display_name="oops\N{SNOWMAN}"><video url="hi"></sequential>'''
@@ -130,7 +130,7 @@ class ImportTestCase(BaseCourseTestCase):
 
         descriptor = system.process_xml(bad_xml)
 
-        self.assertEqual(descriptor.__class__.__name__, 'ErrorDescriptorWithMixins')
+        self.assertEqual(descriptor.__class__.__name__, 'ErrorBlockWithMixins')
 
     def test_unique_url_names(self):
         '''Check that each error gets its very own url_name'''
@@ -164,7 +164,7 @@ class ImportTestCase(BaseCourseTestCase):
         descriptor.add_xml_to_node(node)
         re_import_descriptor = system.process_xml(etree.tostring(node))
 
-        self.assertEqual(re_import_descriptor.__class__.__name__, 'ErrorDescriptorWithMixins')
+        self.assertEqual(re_import_descriptor.__class__.__name__, 'ErrorBlockWithMixins')
 
         self.assertEqual(descriptor.contents, re_import_descriptor.contents)
         self.assertEqual(descriptor.error_msg, re_import_descriptor.error_msg)
@@ -627,7 +627,7 @@ class ImportTestCase(BaseCourseTestCase):
         )
 
     def test_error_on_import(self):
-        '''Check that when load_error_module is false, an exception is raised, rather than returning an ErrorModule'''
+        '''Check that when load_error_module is false, an exception is raised, rather than returning an ErrorBlock'''
 
         bad_xml = '''<sequential display_name="oops"><video url="hi"></sequential>'''
         system = self.get_system(False)
diff --git a/common/lib/xmodule/xmodule/x_module.py b/common/lib/xmodule/xmodule/x_module.py
index 308bd90779..6f411a6153 100644
--- a/common/lib/xmodule/xmodule/x_module.py
+++ b/common/lib/xmodule/xmodule/x_module.py
@@ -1304,11 +1304,11 @@ class XModuleDescriptor(XModuleDescriptorToXBlockMixin, HTMLSnippet, ResourceTem
                 self.xmodule_runtime.xmodule_instance.save()
             except Exception:  # pylint: disable=broad-except
                 # xmodule_instance is set by the XModule.__init__. If we had an error after that,
-                # we need to clean it out so that we can set up the ErrorModule instead
+                # we need to clean it out so that we can set up the ErrorBlock instead
                 self.xmodule_runtime.xmodule_instance = None
 
                 if isinstance(self, self.xmodule_runtime.error_descriptor_class):
-                    log.exception('Error creating an ErrorModule from an ErrorDescriptor')
+                    log.exception('Error creating an ErrorBlock from an ErrorBlock')
                     raise
 
                 log.exception('Error creating xmodule')
@@ -1317,7 +1317,7 @@ class XModuleDescriptor(XModuleDescriptorToXBlockMixin, HTMLSnippet, ResourceTem
                     error_msg=exc_info_to_str(sys.exc_info())
                 )
                 descriptor.xmodule_runtime = self.xmodule_runtime
-                self.xmodule_runtime.xmodule_instance = descriptor._xmodule  # pylint: disable=protected-access
+                self.xmodule_runtime.xmodule_instance = descriptor
         return self.xmodule_runtime.xmodule_instance
 
     course_id = module_attr('course_id')
diff --git a/lms/djangoapps/ccx/models.py b/lms/djangoapps/ccx/models.py
index 16d85ed26f..534f66512f 100644
--- a/lms/djangoapps/ccx/models.py
+++ b/lms/djangoapps/ccx/models.py
@@ -15,7 +15,7 @@ from lazy import lazy
 from opaque_keys.edx.django.models import CourseKeyField, UsageKeyField
 from pytz import utc
 
-from xmodule.error_module import ErrorDescriptor
+from xmodule.error_module import ErrorBlock
 from xmodule.modulestore.django import modulestore
 
 log = logging.getLogger("edx.ccx")
@@ -43,7 +43,7 @@ class CustomCourseForEdX(models.Model):
         store = modulestore()
         with store.bulk_operations(self.course_id):
             course = store.get_course(self.course_id)
-            if not course or isinstance(course, ErrorDescriptor):
+            if not course or isinstance(course, ErrorBlock):
                 log.error("CCX {0} from {2} course {1}".format(  # pylint: disable=logging-format-interpolation
                     self.display_name, self.course_id, "broken" if course else "non-existent"
                 ))
diff --git a/lms/djangoapps/courseware/access.py b/lms/djangoapps/courseware/access.py
index ed389ca575..a9831b57ad 100644
--- a/lms/djangoapps/courseware/access.py
+++ b/lms/djangoapps/courseware/access.py
@@ -65,7 +65,7 @@ from common.djangoapps.util.milestones_helpers import (
     is_prerequisite_courses_enabled
 )
 from xmodule.course_module import CATALOG_VISIBILITY_ABOUT, CATALOG_VISIBILITY_CATALOG_AND_ABOUT, CourseDescriptor
-from xmodule.error_module import ErrorDescriptor
+from xmodule.error_module import ErrorBlock
 from xmodule.partitions.partitions import NoSuchUserPartitionError, NoSuchUserPartitionGroupError
 from xmodule.x_module import XModule
 
@@ -149,7 +149,7 @@ def has_access(user, action, obj, course_key=None):
     if isinstance(obj, CourseOverview):
         return _has_access_course(user, action, obj)
 
-    if isinstance(obj, ErrorDescriptor):
+    if isinstance(obj, ErrorBlock):
         return _has_access_error_desc(user, action, obj, course_key)
 
     if isinstance(obj, XModule):
diff --git a/lms/djangoapps/courseware/module_render.py b/lms/djangoapps/courseware/module_render.py
index a645e514ef..8ce25b9666 100644
--- a/lms/djangoapps/courseware/module_render.py
+++ b/lms/djangoapps/courseware/module_render.py
@@ -94,7 +94,7 @@ from common.djangoapps.util import milestones_helpers
 from common.djangoapps.util.json_request import JsonResponse
 from common.djangoapps.xblock_django.user_service import DjangoXBlockUserService
 from xmodule.contentstore.django import contentstore
-from xmodule.error_module import ErrorDescriptor, NonStaffErrorDescriptor
+from xmodule.error_module import ErrorBlock, NonStaffErrorBlock
 from xmodule.exceptions import NotFoundError, ProcessingError
 from xmodule.lti_module import LTIModule
 from xmodule.modulestore.django import modulestore
@@ -322,7 +322,7 @@ def get_module(user, request, usage_key, field_data_cache,
                                 to the user.
 
     Returns: xmodule instance, or None if the user does not have access to the
-    module.  If there's an error, will try to return an instance of ErrorModule
+    module.  If there's an error, will try to return an instance of ErrorBlock
     if possible.  If not possible, return None.
     """
     try:
@@ -845,11 +845,11 @@ def get_module_system_for_user(
     system.set(u'user_is_beta_tester', CourseBetaTesterRole(course_id).has_user(user))
     system.set(u'days_early_for_beta', descriptor.days_early_for_beta)
 
-    # make an ErrorDescriptor -- assuming that the descriptor's system is ok
+    # make an ErrorBlock -- assuming that the descriptor's system is ok
     if has_access(user, u'staff', descriptor.location, course_id):
-        system.error_descriptor_class = ErrorDescriptor
+        system.error_descriptor_class = ErrorBlock
     else:
-        system.error_descriptor_class = NonStaffErrorDescriptor
+        system.error_descriptor_class = NonStaffErrorBlock
 
     return system, field_data
 
diff --git a/lms/djangoapps/courseware/rules.py b/lms/djangoapps/courseware/rules.py
index 7bf777b389..2e54ef771b 100644
--- a/lms/djangoapps/courseware/rules.py
+++ b/lms/djangoapps/courseware/rules.py
@@ -21,7 +21,7 @@ from openedx.core.djangoapps.content.course_overviews.models import CourseOvervi
 from common.djangoapps.student.models import CourseAccessRole, CourseEnrollment
 from common.djangoapps.student.roles import CourseRole, OrgRole
 from xmodule.course_module import CourseDescriptor
-from xmodule.error_module import ErrorDescriptor
+from xmodule.error_module import ErrorBlock
 from xmodule.x_module import XModule
 
 
@@ -113,7 +113,7 @@ class HasStaffAccessToContent(Rule):
         # (start with more specific types, then get more general)
         if isinstance(instance, (CourseDescriptor, CourseOverview)):
             course_key = instance.id
-        elif isinstance(instance, (ErrorDescriptor, XModule, XBlock)):
+        elif isinstance(instance, (ErrorBlock, XModule, XBlock)):
             course_key = instance.scope_ids.usage_id.course_key
         elif isinstance(instance, CourseKey):
             course_key = instance
@@ -171,7 +171,7 @@ class HasRolesRule(Rule):
             course_key = instance
         elif isinstance(instance, (CourseDescriptor, CourseOverview)):
             course_key = instance.id
-        elif isinstance(instance, (ErrorDescriptor, XModule, XBlock)):
+        elif isinstance(instance, (ErrorBlock, XModule, XBlock)):
             course_key = instance.scope_ids.usage_id.course_key
         else:
             course_key = CourseKey.from_string(str(instance))
diff --git a/lms/djangoapps/courseware/tests/tests.py b/lms/djangoapps/courseware/tests/tests.py
index 87ecf38887..3bad50f5a7 100644
--- a/lms/djangoapps/courseware/tests/tests.py
+++ b/lms/djangoapps/courseware/tests/tests.py
@@ -13,7 +13,7 @@ from six import text_type
 
 from lms.djangoapps.courseware.tests.helpers import LoginEnrollmentTestCase
 from lms.djangoapps.lms_xblock.field_data import LmsFieldData
-from xmodule.error_module import ErrorDescriptor
+from xmodule.error_module import ErrorBlock
 from xmodule.modulestore.django import modulestore
 from xmodule.modulestore.tests.django_utils import TEST_DATA_MIXED_MODULESTORE, ModuleStoreTestCase
 from xmodule.modulestore.tests.factories import ToyCourseFactory
@@ -119,7 +119,7 @@ class PageLoaderTestCase(LoginEnrollmentTestCase):
 
         if check_content:
             self.assertNotContains(response, "this module is temporarily unavailable")
-            self.assertNotIsInstance(descriptor, ErrorDescriptor)
+            self.assertNotIsInstance(descriptor, ErrorBlock)
 
 
 class TestMongoCoursesLoad(ModuleStoreTestCase, PageLoaderTestCase):
diff --git a/openedx/core/djangoapps/content/course_overviews/models.py b/openedx/core/djangoapps/content/course_overviews/models.py
index 416c86ed6e..92922d5d1a 100644
--- a/openedx/core/djangoapps/content/course_overviews/models.py
+++ b/openedx/core/djangoapps/content/course_overviews/models.py
@@ -32,7 +32,7 @@ from openedx.core.lib.cache_utils import request_cached, RequestCache
 from common.djangoapps.static_replace.models import AssetBaseUrlConfig
 from xmodule import block_metadata_utils, course_metadata_utils
 from xmodule.course_module import DEFAULT_START_DATE, CourseDescriptor
-from xmodule.error_module import ErrorDescriptor
+from xmodule.error_module import ErrorBlock
 from xmodule.modulestore.django import modulestore
 from xmodule.tabs import CourseTab
 
@@ -310,7 +310,7 @@ class CourseOverview(TimeStampedModel):
                     "Error while loading CourseOverview for course {} "
                     "from the module store: {}",
                     six.text_type(course_id),
-                    course.error_msg if isinstance(course, ErrorDescriptor) else six.text_type(course)
+                    course.error_msg if isinstance(course, ErrorBlock) else six.text_type(course)
                 )
             else:
                 log.info(
diff --git a/openedx/core/djangoapps/content/course_overviews/tests/test_course_overviews.py b/openedx/core/djangoapps/content/course_overviews/tests/test_course_overviews.py
index 6db935d35d..96eb908749 100644
--- a/openedx/core/djangoapps/content/course_overviews/tests/test_course_overviews.py
+++ b/openedx/core/djangoapps/content/course_overviews/tests/test_course_overviews.py
@@ -36,7 +36,7 @@ from xmodule.course_module import (
     CATALOG_VISIBILITY_CATALOG_AND_ABOUT,
     CATALOG_VISIBILITY_NONE
 )
-from xmodule.error_module import ErrorDescriptor
+from xmodule.error_module import ErrorBlock
 from xmodule.modulestore import ModuleStoreEnum
 from xmodule.modulestore.django import modulestore
 from xmodule.modulestore.tests.django_utils import ModuleStoreTestCase
@@ -356,13 +356,13 @@ class CourseOverviewTestCase(CatalogIntegrationMixin, ModuleStoreTestCase, Cache
 
     def test_get_errored_course(self):
         """
-        Test that getting an ErrorDescriptor back from the module store causes
+        Test that getting an ErrorBlock back from the module store causes
         load_from_module_store to raise an IOError.
         """
-        mock_get_course = mock.Mock(return_value=ErrorDescriptor)
+        mock_get_course = mock.Mock(return_value=ErrorBlock)
         with mock.patch('xmodule.modulestore.mixed.MixedModuleStore.get_course', mock_get_course):
             # This mock makes it so when the module store tries to load course data,
-            # an exception is thrown, which causes get_course to return an ErrorDescriptor,
+            # an exception is thrown, which causes get_course to return an ErrorBlock,
             # which causes get_from_id to raise an IOError.
             with self.assertRaises(IOError):
                 CourseOverview.load_from_module_store(self.store.make_course_key('Non', 'Existent', 'Course'))