We have a client running our .NET application which connects to SQL Server 2005 on the backend. A few weeks ago the database crashed and the whole server had to be rebooted. This happened again today and I got the log file from their DBA which seriously offered no clue as to what's really going on.

I searched online and only found one other mention of this on a Russian programmers forum which I can't understand. Here's the non-informative log message:

SQL Server Assertion: File: T:\Yukon\sql\ntdbms\storeng\dfs\manager\lckmgrp.h, line=675 Failed Assertion = 'm_iteratorInSafeState'. This error may be timing-related. If the error persists after rerunning the statement, use DBCC CHECKDB to check the database for structural integrity, or restart the server to ensure in-memory data structures are not corrupted.

Any ideas?


After a bit more digging to another error that had a similar signature, I was able to determine the client needed to upgrade to Service Pack 3 since they were still on SP 1. This was also confirmed by Microsoft support. Thanks for your input!


Given that you've hit an internal assertion failure, you need to tell Microsoft about it.

Contact Product Support Services, and see if there is an internal hotfix for the issue. Since it's not your fault, it won't cost you anything.

At the very least Microsoft would like to know about it.

  • If the fault is hardware memory corruption, is not MS fault and it may cost you something ;) – Remus Rusanu Oct 30 '09 at 20:46
  • Touché, but doubtful. You'd see many other errors, before this very intermittent single assertion failure. – Ian Boyd Nov 2 '09 at 14:45

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