Unreadable content error message
People at my organization work with a lot of templates. We have not had problems with the templates until recently. Now, files sporadically give an "unreadable" content error. (See photos below, with file name blacked out.)
The top error message occurs when trying to open a document. If you click "yes," a copy of the document will open, but saving the copy creates a second corrupted file. If you click "no," the bottom error message pops up.
The IT manager and I have tried various fixes. The Text Recovery Converter produces a garbled file full of symbols. Open and Repair generates another corrupted file. Opening a new file and using Insert >Text from File (or doing Ctrl + A and copy/paste) creates another corrupted file.
The only fix that works so far is to change the file extension from .docx to .rtf and back again. This removes all content controls, which means the drop-down menus in the file are no longer available. This, obviously, is not preferable.
Can anyone help me with what the problem might be? Could it be macro settings or Trust Center settings on individual employees' devices? Could it be compatibility problems from different versions of Windows (some employees have 10, while others have 11)? Is it user error? If the problem were the template itself, none of our files should work, right? Which leads me to believe the problem lies with individual users somehow.
This is driving us nuts, because this template has been working for close to a year. Now, all of a sudden, we're getting a bunch of corrupted files.
Thanks!