I have had SQL Server 2012 on my server for about 6 months. Over the last few weeks, a problem has developed, whereby the SQL Server stops functioning, and any attempt to connect or query returns the error:
[SqlException (0x80131904): A severe error occurred on the current command. The results, if any, should be discarded.]
The SQL Server service is completely non-responsive. The only way to recover is to kill sqlservr.exe and restart the service. This happens annoyingly frequently, every couple of days or so.
I have looked through the Windows application logs, and found no clues. There are no errors reported; all I see are the application errors that start getting reported when the app can no longer connect to SQL Server.