http://coursework-s1.stanford.edu:29080 (nightly qa instance, rc4)
When reviewing a submitted assessment (either by clicking on the assessment title or the Feedback link), you can click the Remove link next to an uploaded file to get the remove-confirmation screen.
From there, if you click remove, the uploaded file is removed. If you click Cancel, you get a messed-up screen. (no exception in logs)
Steps to reproduce:
1) Take an assessment with a file upload question as a student; upload a file to answer that question.
2) Submit the assessment for grading
3) Return to the list of available assessments
4) Click on the title of the assessment you just took in the review list
5) Find the file upload question and click on the Remove link next to the file.
Action: The "remove" link should be disabled in review.