Confirm the Firebird Services are at "Started" status in the Administrator Services
Firebird Guardian (if it exists)
Firebird Server
If they are started, re-start them and check if errors still persist
If they are not started, start the Guardian (if it exists) and confirm the Server also starts
If they are not in the Services, confirm you are on the server where HowNow database is stored, then you need to re-install Firebird