What if your files got affected by this plague (Ransomware)? It is unlikely that you can decrypt the files, even after paying a ransom.
First thing first – the command DBCC FLUSHAUTHCACHE only is supported on SQL Azure. The behavior of change of password is a bit different on SQL Azure.
In this blog we would talk about fixing error 7416 – Access to the remote server is denied because no login-mapping exists.