New collectives are encrypted, but not decrypted


In just noticed that for some reason all collectives that I created since 06/2023 are encrypted while older ones apparently aren’t.
Until recently I didn’t notice this, since I could just work with all the documents / pages in my collectives, as it should.
But now, when I try to open some of the documents in my collectives I see an encryption header (HBEGIN:oc_encryption_module:OC_DEFAULT_MODULE:cipher:AES-256-CTR:signed:true:encoding:binary:HEND), followed by a lot of lines and ended with some garbage.
Other documents in my collectives open just fine.

That made me investigate this further and in the end I found out that the ones I can still open are not encrypted while the others are encrypted.
It’s unclear to me however why the more recent ones (i.e. the encrypted ones) suddenly don’t get decrypted.

Here are some more details:

All files of my collectives are stored under /mnt/volumes/86e3d75d7a56496b91a5e41e80fab174/appdata_ocs7vgdq30tv/collectives
which contains a numerical folder (/1, /2, /3, …) for each collective, e.g.:
/mnt/volumes/86e3d75d7a56496b91a5e41e80fab174/appdata_ocs7vgdq30tv/collectives/6 is my “Development” collective and it contains following documents (= .md files):
/ (readable, because not encrypted)
/ (readable, because not encrypted)
/ (unreadable, because encrypted)

So until recently I could just open the document while now I do get the encryption garbage, as mentioned at the top of this post.

In the subfolder files_encryption under the data foldler, I found keyShares for each collective document that appears to be encrypted, e.g. for the document mentioned above, this is:

So, is there any way I can (manually) decrypt those encrypted collective documents?

I already tried to use the decrypt-all-files.php script available at:, but that doesn’t seem to support files from collectives. It just skips them.

I’m on Nextcloud 27.1.5 running in docker (via Cloudron)