Login failed for user 'NT AUTHORITY\SYSTEM'. SharePoint 2007

Friday, 8 February 2008 23:08 by RanjanBanerji

Note: The error I am talking about can occur due to various reasons.  This post is specific to SharePoint 2007

On our SQL Server box we got hundreds if not thousands of Login failed for user 'NT AUTHORITY\SYSTEM' errors in the event log.  Looking at the SQL Logs I determined that these were Error: 18456, Severity: 14, State 16.  Great so what does that mean?

A little more research showed that SharePoint runs a job on SQL Server that deletes expired Sessions from the Shared Services Database.  If you had been moving databases, removing SSPs, etc you may end up in a situation where an old SSP Shared Service Database no longer exists but the job to delete its expired sessions is still running.  Aha!!!!! and there you have this error showing up every minute of so.

To fix the problem go to SQL Server Management Studio, Go to SQL Server Agent, Open Jobs and disable or delete jobs that point to Shared Services databases that no longer exist.