The FogBugz database is down or could not be found.

Error: -2146232060: Cannot open database "fogbugz" requested by the login. The login failed. Login failed for user 'shopuser_fb'.

For security reasons, this cannot be fixed over the web.

Please edit the registry on the FogBugz server. The setting you want is HKEY_LOCAL_MACHINE\SOFTWARE\Fog Creek Software\FogBugz\C:/Program Files (x86)/FogBugz/website\sConnectionString.
Common connection strings can be found at connectionstrings.com. (Also please note that if your SQL machine is on a different server than your web server, you may have to use SQL Server Authentication, and not Integrated Authentication.)

To use SQL Server, set this to Server=server;Initial Catalog=database;MultipleActiveResultSets=true;Integrated Security=SSPI; for Integrated Authentication
or Server=server;Initial Catalog=database;MultipleActiveResultSets=true;User Id=sqlserveruser;Password=sqlserverpassword; for SQL Server Authentication

To use Access, set this to Provider=Microsoft.Jet.OLEDB.4.0;Data Source=filename