Encryption error - Cannot decrypt this file

I have enabled per-user encryption in Nextcloud 29. For each new photo that I upload, I get the following error:

{"reqId":"XBvnEJsRSLOKLbEVuDR0","level":3,"time":"2024-06-21T15:02:33+00:00","remoteAddr":"","user":"--","app":"no app in context","method":"","url":"--","message":"Cannot decrypt this file, probably this is a shared file. Please ask the file owner to reshare the file with you.","userAgent":"--","version":"29.0.1.1","data":[]}

I do not know how to determine which application or where in Nextcloud the error is being triggered. Can you help me investigate this further?

There was at least one fix in this area in the latest maintenance release (29.0.3) which you would not have in 29.0.1. Please confirm you have the same behavior in the latest maintenance release.

I have enabled per-user encryption in Nextcloud 29.

Are you saying you just switched to per-user from master-key mode in v29 or that you just enabled encryption for the first time in v29?

For each new photo that I upload, I get the following error:

Is the folder you’re uploading photos to a shared folder? Or is there anything else special about the folder? e.g. groupfolder/etc)

I installed version 29.0.3 a couple of days ago, but the problem is still present. When a new photo is uploaded and the cron.php job starts, a new error log is generated.

When I enabled the master key, the problem did not occur. However, since I enabled the per-user key, my logs are full of “decryption error” messages.

The folder where I upload the photos is the default Android folder: “Personal Files/instaUpload/Camera”.

I don’t know how to extend the logs to discover where the problem is.

Did you decrypt all files prior to switching?

Are you using LDAP or anything like that for authentication?

I have not decrypted any files since switching from the master key to the per-user key. Is it required? Should I try? Maybe this is the problem!

No, I do not use LDAP. It is a self-hosted project. At the moment, I have just two users: the administrator and a normal user (my user).