Fixed some isinstance errors with opaque-keys

common/lib/xmodule/xmodule/tests/test_import.py

@@ -438,12 +438,15 @@ class ImportTestCase(BaseCourseTestCase):
         print("course errors:")
 
         # Expect to find an error/exception about characters in "®esources"
-        expect = "Invalid characters"
+        expect = "UnicodeEncodeError"
         errors = [
             (msg.encode("utf-8"), err.encode("utf-8"))
             for msg, err
             in modulestore.get_course_errors(course.id)
         ]
+        for msg, err in errors:
+            print("msg: " + str(msg))
+            print("err: " + str(err))
 
         self.assertTrue(any(
             expect in msg or expect in err