Unable to update Sonarr v3

Sonarr version (exact version): 3.0.3.750
Mono version (if Sonarr is not running on Windows):5.20.1.34
OS: Synology DSM 6

when i click on update in sonarr, i see that it is extracting the update, then it says failed.

am i suppose to give any specific folders access to sonarr?

If I recall correctly, that version is broken (in terms of being able to update itself) and you’ll have to do it manually.
Edit: sorry, that was …712

What do the debug logs show?
Also check the update logs.