Upgrade from v2 to v4 - search broken?

Sonarr version (exact version): 4.0.12.2823
OS: Windows 7
Debug logs: PrivateBin
Description of issue:

I’ve upgrdaded from an old v2 installation to the latest version and it seemed to go ok but when I try to search for any episodes, it just seems to hang and the logs are showing this: (example of searching for episode of Tehran).

Could not get paste data: Paste does not exist, has expired or has been deleted.

Best guess, corrupt DB that needs to be repaired.

Any suggestions for fixing it? Do I just follow the repair guide in the FAQ?

Or should I just wipe it all and start again? (Can I just delete the .db file or is a reinstall needed to get a fresh DB copy?)

I’m just guessing because I have no idea what your logs actually show. If it’s indicating there is corruption then the repair guide in the FAQ is good, Plex’s repair guide may have some additional suggestions as well that could help.