diff --git a/common/lib/capa/capa/responsetypes.py b/common/lib/capa/capa/responsetypes.py
index 9332417197..f9cfa0281c 100644
--- a/common/lib/capa/capa/responsetypes.py
+++ b/common/lib/capa/capa/responsetypes.py
@@ -1597,9 +1597,8 @@ class NumericalResponse(LoncapaResponse):
             student_float = evaluator({}, {}, student_answer)
         except UndefinedVariable as undef_var:
             raise StudentInputError(
-                _(u"You may not use variables ({bad_variables}) in numerical problems.").format(
-                    bad_variables=undef_var.message,
-                )
+                _(u"Answers can include numerals, operation signs, and a few specific characters, "
+                  u"such as the constants e and i.")
             )
         except ValueError as val_err:
             if 'factorial' in val_err.message:
@@ -1608,7 +1607,7 @@ class NumericalResponse(LoncapaResponse):
                 # ve.message will be: `factorial() only accepts integral values` or
                 # `factorial() not defined for negative values`
                 raise StudentInputError(
-                    _("factorial function evaluated outside its domain:"
+                    _("Factorial function evaluated outside its domain:"
                       "'{student_answer}'").format(student_answer=cgi.escape(student_answer))
                 )
             else:
@@ -3104,7 +3103,8 @@ class FormulaResponse(LoncapaResponse):
                     cgi.escape(answer)
                 )
                 raise StudentInputError(
-                    _("Invalid input: {bad_input} not permitted in answer.").format(bad_input=err.message)
+                    _(u"Answers can include numerals, operation signs, and a few specific characters, "
+                      u"such as the constants e and i.")
                 )
             except ValueError as err:
                 if 'factorial' in err.message:
@@ -3119,7 +3119,7 @@ class FormulaResponse(LoncapaResponse):
                         cgi.escape(answer)
                     )
                     raise StudentInputError(
-                        _("factorial function not permitted in answer "
+                        _("Factorial function not permitted in answer "
                           "for this problem. Provided answer was: "
                           "{bad_input}").format(bad_input=cgi.escape(answer))
                     )
diff --git a/common/lib/capa/capa/tests/test_responsetypes.py b/common/lib/capa/capa/tests/test_responsetypes.py
index 982924eb61..79f5eeebbb 100644
--- a/common/lib/capa/capa/tests/test_responsetypes.py
+++ b/common/lib/capa/capa/tests/test_responsetypes.py
@@ -1669,8 +1669,9 @@ class NumericalResponseTest(ResponseTest):  # pylint: disable=missing-docstring
         problem = self.build_problem(answer=4)
 
         errors = [  # (exception raised, message to student)
-            (calc.UndefinedVariable("x"), r"You may not use variables \(x\) in numerical problems"),
-            (ValueError("factorial() mess-up"), "factorial function evaluated outside its domain"),
+            (calc.UndefinedVariable("x"), "Answers can include numerals, operation signs, "
+                                          "and a few specific characters, such as the constants e and i."),
+            (ValueError("factorial() mess-up"), "Factorial function evaluated outside its domain"),
             (ValueError(), "Could not interpret '.*' as a number"),
             (pyparsing.ParseException("oopsie"), "Invalid math syntax"),
             (ZeroDivisionError(), "Could not interpret '.*' as a number")
diff --git a/common/lib/xmodule/xmodule/capa_base.py b/common/lib/xmodule/xmodule/capa_base.py
index f778316bfb..f860023a4e 100644
--- a/common/lib/xmodule/xmodule/capa_base.py
+++ b/common/lib/xmodule/xmodule/capa_base.py
@@ -1238,7 +1238,7 @@ class CapaMixin(CapaFields):
             # without a stack trace
             else:
                 # Translators: {msg} will be replaced with a problem's error message.
-                msg = _(u"Error: {msg}").format(msg=inst.message)
+                msg = inst.message
 
             return {'success': msg}
 
diff --git a/common/lib/xmodule/xmodule/css/capa/display.scss b/common/lib/xmodule/xmodule/css/capa/display.scss
index 54bd748c38..30a9a90406 100644
--- a/common/lib/xmodule/xmodule/css/capa/display.scss
+++ b/common/lib/xmodule/xmodule/css/capa/display.scss
@@ -1104,7 +1104,7 @@ div.problem {
 
     .notification-message {
       display: inline-block;
-      width: flex-grid(6,10);
+      width: flex-grid(7,10);
       // Make notification tall enough that when the "Review" button is displayed,
       // the notification does not grow in height.
       margin-bottom: 8px;
diff --git a/common/lib/xmodule/xmodule/tests/test_capa_module.py b/common/lib/xmodule/xmodule/tests/test_capa_module.py
index 73b716de68..c79b7d16f6 100644
--- a/common/lib/xmodule/xmodule/tests/test_capa_module.py
+++ b/common/lib/xmodule/xmodule/tests/test_capa_module.py
@@ -818,7 +818,8 @@ class CapaModuleTest(unittest.TestCase):
                 result = module.submit_problem(get_request_dict)
 
             # Expect an AJAX alert message in 'success'
-            expected_msg = 'Error: test error'
+            expected_msg = 'test error'
+
             self.assertEqual(expected_msg, result['success'])
 
             # Expect that the number of attempts is NOT incremented
@@ -886,7 +887,8 @@ class CapaModuleTest(unittest.TestCase):
                 result = module.submit_problem(get_request_dict)
 
             # Expect an AJAX alert message in 'success'
-            expected_msg = u'Error: ȧƈƈḗƞŧḗḓ ŧḗẋŧ ƒǿř ŧḗşŧīƞɠ'
+            expected_msg = u'ȧƈƈḗƞŧḗḓ ŧḗẋŧ ƒǿř ŧḗşŧīƞɠ'
+
             self.assertEqual(expected_msg, result['success'])
 
             # Expect that the number of attempts is NOT incremented