I had this same issue this morning and the fix worked for me. Building upon the other instructions provided above.
To help everyone else here’s the steps i followed:
Install SSH server from addons and login over SSH or use web console
> ha core stop > cd /config > ls -al (this should show you a listing of all the files including home-assistant_v2.db > sqlite3 ./home-assistant_v2.db ".dump" | sqlite3 ./home-assistant_v2.db.fix > mv ./home-assistant_v2.db ./home-assistant_v2.db.broken > mv ./home-assistant_v2.db.fix ./home-assistant_v2.db > ha core start
Go back to main console, check logs and history via ui if fixed
Hope that helps.