I recently had a curious case of misleading login errors.

When I attempted to connect to a SQL Server instance hosting an Availability Group (AG) replica I connected without error via SSMS. However, when trying to connect via the AG Listener I was getting the error

Error connecting to [AGListenerName]

additional information: Login failed. The login is from an untrusted domain and cannot be used with Windows authentication. (Microsoft SQL Server, Error: 18452)

The official documentation was not helpful and sadly this isn’t an 18456 error so we can’t access the excellent content from Aaron Bertrand on Troubleshooting Error 18456 which covers all the failed login permutations of Error State and Error Severity.

Noone else was suffering this problem and after a little consideration of anything security related that I had witnessed recently I realised that the cause was that I had recently changed my domain logon password and had not restarted SSMS. A quick restart of SSMS (I actually restarted my jump server just to give it a refresh too!) andeverything was back to normal.