Sync Problems with Nextcloud: No such master key

I'm all new to Joplin trying to get away from Apple notes and iCloud. Unfortunately I have a huge sync problem right from the start.
I'm using version 2.8.8 on a MacBook Pro (2020), MacOS 12.3.1. I want to sync it to a managed Nextcloud.
Before synquing I imported all my notes. Then I chose Nextcloud as sync target and entered all the necessary data. Result: "Success! Synchronization configuration appears to be correct."
But when I hit "Synchronize": Completed: 13.06.2022 21:12 (3s)
Last error: Error: No such master key: ........
Can anyone help, please?

Hey there, maybe you accidentally enabled e2ee encryption? It cannot work without the master key. Make sure it's disabled in encryption options and try again.

Cheers!

Thanks for your reply. I disabled encryption. Same problem after sync: "Completed: 14.06.2022 20:31 (2s)
Last error: Error: No such master key: f1549da0...."
:frowning:

Got it, have you tried already any other cloud so far (dropbox, onedrive, etc)?

Out of curiousity, do you have any data in that Nexcloud account from any other device?

Good questions!
Nextcloud is working fine with other data.
Dropbox isn't synquing either with Joplin.
Looks like it's not a Nextcloud problem.

Connection to Dropbox did work, though. All the Joplin files where generated in Dropbox but no data was updated. Exactly the same happened with Nextcloud.

That's weird, how do you feel about starting again with clean client?
I.e. creating a full backup, cleaning the local data, importing the backup and reuploading the data into the cloud

Btw, Victor plugin might help with a complete data wipe here

Used Viktor plug in and clicked delete. Unfortunately it didn't manage to delete folders and sync preferences. Any idea how I get a complete data wipe?

Everything's getting weirder and weirder.

Well, you may try deletion with Victor once again and if it still doesn't work, try deleting the profile folder ~/.config/joplin and ~/.config/joplin-desktop

Yes! It worked! I deleted ~/.config/joplin-desktop which cleared all data. Now Nextcloud-Sync works! I hope, it'll work now with my mobile devices, too. Thank you so much for your help, time and effort!