Preview unable to open PDF attachments directly from Mail.

I just ran into this EXACT issue again today. It looks like specifically Preview is being denied permission to access files of certain types. This appears to be Apple’s fault. The “fixes” I’ve tried so far only temporarily solve the issue but something I didn’t mention the other day is to try the following:

Open System Preferences:
Security & Privacy
Select Privacy in the menu
(Click the lock in the bottom left to unlock)
Select Full disk Access from the list on the left.
Click the plus sign to add Preview to that list.
Check the box next to preview if it’s not already checked.



That may resolve it. I’ve reported the issue to Apple and 12.5 Monterey is releasing soon. The bad news is that I’ve seen this in both Monterey and Big Sur so I don’t have high hopes they’ll resolve this soon. There are other things we can throw at it but it’s definitely an annoying issue.

Temporary solution looks like dragging the attachment to the desktop and opening from there.