Quuzuu

It seems what solved it was an auto-update of the client.

I somehow auto-updated to the version below, and the issue is gone:

10.65.3-win-ddl-public (20231103200848)
Editor: v176.15.0
Service: v1.77.1

Whenever I try to delete an old note, the deletion will fail, and this red alert shows up.

It happens on all notes in all notebooks, tested in both Web and Windows version. Except if I create a new note and immediately delete it, it'll work.

My test in Windows was done with a brand new install. Version numbers seen in Windows:

10.65.2-win-ddl-public (20231027153932)
Editor: v176.15.0
Service: v1.77.0