The list of assignments shows an attachment icon on the left if there is a file attached to the assignment. This icon remains if the attachment is removed.
- Create an assignment with an attached file.
- Edit the assignment
- Click the Add / Remove Attachments button.
- Click the Remove link for the attached file.
- Click Continue.
- Click Post to save the modified assignment.
Logically, if the attachment is removed, the icon should be gone.