Error: SQLite Database Error

Joplin Version: Joplin for Desktop, Joplin 1.2.6 (prod, linux)
OS: Ubuntu Desktop 20.04 LTS (Linux x2020-ws-1001 5.4.0-52-generic #57-Ubuntu SMP Thu Oct 15 10:57:00 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux)
User Action: Synchronisation of newly created note.
Error Message: Abgeschlossen: 27/10/2020 21:30
Letzte Fehlermeldung: Error: Error: SQLITE_READONLY: attempt to write a readonly database: DELETE FROM sync_items WHERE sync_target = ? AND item_type = ? AND item_id = ?: 6,1,411332d133fe4abb836cf2294d359e45


  1. What's wrong here?
  2. How can I fix that?