Microsoft issued a warning about a bug affecting Microsoft 365's Office Word app where saving a document using a specific file name would end up deleting it instead of saving it. The combination might be odd as it involves the hashtag character in the file name and capitalization of the file's extension- but it exists and needs to be addressed regardless.
According to Microsoft, this bug gets triggered when the .docx extension is capitalized with the hashtag symbol in its file name. Microsoft further adds a finding that the issue occurs after saving the file when prompted to click X to close the Word app. However, manually saving the file with '.DOCX' and a hashtag character in the file name does not reproduce the automatic deletion.
Thankfully, the deletion is not permanent, as the Recycle Bin can restore the file. Besides restoring it, Microsoft suggested two workarounds- save the file manually before closing Word, and another is to enable the option "Don't show the Backstage when opening or saving files with keyboard shortcuts" in Word.
The bug is specifically present with Microsoft 365 version 2409, as confirmed by Microsoft. It is peculiar that the bug only eats the Word document using .docx in all caps with a hashtag character in the file name. Microsoft didn't explain the cause of this bug specifically with this build, as it is still under investigation. No other combination has been discovered that reproduces auto-deletion yet.
Having a document deleted automatically is a nightmare, mainly when the application is used for many important work. It wouldn't be surprising to see users have a hashtag in the file name by someone whose profession is associated with social media, as the character is used for tagging in leading social media apps like Instagram and X, formerly Twitter. Users are likely unaware of this even if it goes to the Recycle Bin.
Therefore, no matter how odd or seemingly rare, it is always best to kill the bug before it eats your homework.