1. Log in as admin
2. Open "My private files"
3. Add few files and save changes
4. Visit "My private files" page
5. In another tab, logout and login back
6. Click "create folder" and enter name
7. Nothing happens, no error or warning is displayed.

FYI:
Clicking add shows "Incorrect sesskey submitted, form not accepted!", IMO it can be improved, as a novice doesn't understand sesskey. Also, Filepicker should be closed on clicking ok on error message, or should not open at first place.