Files showing 'zero byte" as size - un-openable

Those aren’t files, they’re stubs. There is nothing in those.

Whether this is the cleaning app gone wrong or is something gone wrong within iCloud Files is unclear. I’ve encountered problems with both, and I don’t immediately trust cleaning apps to coexist well with file sync services including iCloud, OneDrive, Dropbox, or otherwise.

With macOS 14, Apple operates iCloud Files in two modes, depending on the Optimize Mac Storage setting, too. Apps that are poking directly at low-level file system interfaces and aren’t expecting that Apple setting—this includes cleaner apps—can end badly.

Do you have backups of this data? If so, that is where this is headed.

And has been mentioned above, I would discourage adding cleaner apps to the mix.

avidalone wrote:

I recently went to open an older file in my documents folder and it was reported as corrupt. Upon looking at list view I see several groups of documents are zero bytes and un-openable.

They seem to be pdf, jpg, graffle, and numbers files. this is only in my Document's folder and I believe all of the files are stored on iCloud.

It seems arbitrary. It's some files and not others and I can't really see a cause, like before a date or just one app. I don't know when this occurred, but it must have been recently. I did upgrade to Sonoma a couple of weeks ago. Tried disk utility. I have CleanMyMacX and tried to repair permissions to no avail.

I've searched here, but no consistent cause is apparent.

Has anyone seen this?

<CleanMyMacX>

one of the worst. Excellent marketing campaign, with a strong willingness to take your money.

Uninstall all third party apps that are Cleaners/Optimizers/VPN/Anti-Virus

all known to cause issues on the macOS

if you have a time machine back you can restore individual files

Restore your Mac from a backup you can use it to restore any or all of your files...

ref: How to restore your Mac from a Time Machine backup

"CleanMyMac" claims another victim.