Per Downgrading / reverting to a lower version trying to downgrade across 2.0.3.12 will cause a database version error message. You can probably downgrade to 2.0.3.12, but not lower than that.
You’ll probably need to try installing the 2.0.4.1 deb package again, and if it still doesn’t work, we can try to fix it at that version.
Note that re-installing the package should NOT affect your existing backup jobs or settings - but backing them up first is hardly ever a bad idea. 
(If you want to do so, just copy your *.sqlite and *.json files somewhere other than where they are now.)