“File_Name.numbers” is damaged and can’t be opened.

Thanks again Badunit.

"Versions" of the file that were automatically saved when data was added to the file. You can access archived versions from the file tab or in this case, from the dialogue box that appears while trying to open the file (see screen shots below). You can also see the "versions" timeline for the "damaged" file in the larger screen shot below. Every version I attempt to open displays "damaged and can't be opened" or "unable to open version."

This is crazy...I've stored Numbers spreadsheets in the Cloud for years, but have never encountered this "damaged and can't be opened" scenario before. Again, this file will not open on any device...iMac, MacBook, iPad Pro, iPhone X, or straight from iCloud opened in Safari. Before yesterday, it would open on all of the above devices.

Thanks for replying Badunit!

So no previous (archived) versions of this file will open...all versions give the same "damaged and can't be opened" message. I routinely use Numbers spreadsheet files stored on iCloud because they easily update across all my devices as well as coworkers' devices when collaborating. This particular spreadsheet file has been in use for almost 5 years and has been accessible and functioning without a problem until yesterday. All devices are up to date and have been rebooted. I've attempted to download the file to my iMac, email the file to my daughter's MacBook, rename the file, and have tried to restore previous versions repeatedly, but the file refuses to open and gives the same message every time. This is the first time I've ever encountered this problem and am not really sure what else can be done at this point...unless someone knows how to access/repair damaged Numbers files.

I've searched this forum and found a post describing a similar problem, but it appeared to not solicit a solution.