Setup: 1. Create an course with a student and teacher. 2. Create an assignment in the course. 3. Login as the teacher and grade the student in the assignment. Test 1 - importing 4. On the course page, hide the assignment.  5. From the course settings menu choose "Import".  6. Import the assignment from the same course to the same course. 7. Verify you do not see "Invalid course module ID" during the import. 8. Verify you can view both assignments and the gradebook without errors.  Test 2 - deleting modules. 9. Create an activity of each of the following types and manually grade a student for each one in the gradebook. Database Lesson External Tool (does not need to be valid - http://www.google.com/  will be OK) SCORM (example file attached to this issue) Workshop 10. Delete each of these activities 11. Verify there are no errors shown during deletion.