Affects Version/s: Master
Steps to Reproduce:
1. Navigate to Content -> Documents and Media
2. Add a new Basic Document
3. Create a non-file titled "nofile.jpg" with no file attached; then Publish
4. Click on the title/link of the new document which will display its preview window
Preview is not generated (with possible information message that states the file can't be previewed)
Preview is not generated but a message will appear that will never go away: "Generating preview will take a few minutes."