Partial decryption -- how to decrypt fully?

for some practical reasons i switched back from the encryption mode to the encryption mode. but i ran time and again in sync errors related to encrypted files.

so i decided to delete the unencrypted file (the one causing an error while syncing) on the sync target. this caused another error: GET Could not open file (Exception Sabre\DAV\Exception\ServiceUnavailable) (503): <?xml version="1.0" encoding="utf-8"?> <d:error xmlns:d=“DAV:” xmlns:s=“”> <s:exception>Sabre\DAV\Exception\ServiceUnavailable</s:exception> <s:message>Could not open file</s:message> </d:error>

apparently, joplin is still looking for this file, even though i wanted to get rid of it. i also tried to locate the other non-decrypted md files on the sync target. right now, there are 6 of them. how can i delete them or rather uncrypt them without running in the next error (as above)?

update: the previous error was the following
Letzte Fehlermeldung: Error: On file Unknown type: 13

since i managed to restore the file from backup, i’m getting now again this error while syncing…

Make sure you run the latest version on all your devices.

yes, i updated my client, this way i got rid of the error message! (but very few encrypted files remain.)