Ring.3dm is not a Rhino file

This is driving me crazy!

Got this message when trying to open a file a minute ago:

/Users/danielskold/Documents/Paula Lindgren/3D/SPECIALBESTÄLLNINGAR/Marie Görling/ring.3dm is not a Rhino file.

The stack of files that are unopenable are just piling up. I have been working on this file for 2 days, and now it just broke.
I suspect it has something to do with cash running out or something like that, but i have lots of files that for no reason has broken down. I have been saving manually periodically, and then, suddenly, the file can not be opened anymore.
Why is this happening? What can I do about it?
I have tried to open the files in a windows computer too, but no, they are just broken.

Hello - please send one of these to tech@mcneel.com. The smallest one… Please also include a link back here in your comments.

-Pascal

Thank You Pascal. I have transferred a file via Wetransfer. I hope that is ok. It was too big to be attached in an email.

/Daniel

Hi Daniel - I have your file, thanks. Are you saving to a local hard drive or to a Google Drive or other synced drive?

-Pascal

Super!
I am saving locally, but syncing it to iCloud for backup.

Hi Daniel - there is a big chunk of the file missing. I would be suspicious of the sync, off hand, especially if it is automatic. Are all the files that have gone bad saved and synced/backed up the same way? I don’t know what the definitive test would be but I would save so some non-synced folder and see if the problem simply stops - do your backing up manually for a while. I understand that is not a real solution but a test to see if indeed the syncing is the problem.

-Pascal

Ok. I will try to disable the sync and see if that solves it short term. Thank you.
But for the future I think this must work. My next computer will have less local storage, and I guess that is where we are heading all of us…

Hi Daniel - please report back if you find that it works better, or not - as you say, we will need to figure out the best way to handle all of this syncing, if indeed that is causing the problem.

thanks,

-Pascal