Sonarr Won't Open on Windows even after reinstall (Unhandled Exception)

Sonarr version (exact version): 3.0.9.1549
Mono version (if Sonarr is not running on Windows):
OS: Windows
Debug logs:
Description of issue:

Sonarr has been running smoothly on this windows 10 PC for a long time. All of a sudden now - when I try to launch Sonarr, the UI doesn’t show up and the process also start open (when i check the task bar it’s not there either).

I tried reinstalling Sonarr and that doesn’t resolve it. Now that I’ve reinstalled I don’t have a logs folder, the sonarr folder only contains the “bin” folder. My PC is up to date.

If i try to run Sonarr console - I get an error message here Untitled hosted at ImgBB — ImgBB something about an unhandled exception with nzb drone.

I also tried installing older versions of sonar (back to 3.0.8.1536) and it still behaves the same way

thanks for any ideas on how to resolve this!