Nextcloud errors : Bad signature, 500 and 403 Errors

[supportlevel]

Nextcloud version: 18.0.4
Operating system and version: Ubuntu 18.04
We’ve enabled encryption.
When I try to copy or to move document files (from group folder), several errors appear :
“OCP\Encryption\Exceptions\GenericEncryptionException: Bad Signature”
“500 Internal error” and “403 Forbidden”.

Is there any link with the trash?
it seems that when the trash, which is not encrypted, is emptied, the error messages disappear.
However, we have this problem : there are files in the trash that cannot be deleted.

Before activating the encryption, everything worked correctly.

Thank you for your support

[rhua]

Have a similar issue on Nextcloud installation with some folders connected to S3 buckets for external storage. Although I am still not sure how the trash bin pertains to our issue, I began a thread several days ago and recommend that those with a similar issue reply to that thread: Files could not load after being restored from trash

By the way, all three of the errors persisted even after I emptied the trash bins of both the affected user and the admin account.

[tflidd]

Nextcloud creates a signature of each file and uses information of the file and the database. With bad signature, you can’t decrypt and open files. Question is how you end up with broken signatures, is there a backup restore or filecache-rescan that breaks things? So you have to find out, how you end up there. Are all files affected? If not, what is different, were they opened in a special program, copied from a share, synced with a special device, …