URGENT – user-uploaded files deleted randomly?

We just launched our application last week, and things were running smoothly, until the site admins today reported that all user-uploaded files from before today are all gone? The directory associated with the user ID in /uploads/ultimatemember is simply gone for any user who registered before today, and on the user profile it just says “This file has been removed.” Screenshot of the directory included, there should be user IDs all the way back to 55 or so.

We can, of course, revert to a backup, but will lose all the applicants from today. As far as I can tell, there is no server issue that would cause this to happen. Please help!

The page I need help with: [log in to see the link]