On Monday (1/14) we started seeing reports of problems with KB2756920 (MS13-004 ) affecting 2008 R2 servers, with .NET 3.5.1.
KB2756920 is MS13-004 for .NET Framework 3.5.1 on Windows 7 and Windows Server 2008 R2
How to fix
We have tested Option 1 (uninstalling KB2756920) and it does correct the problems with Exchange 2010. We have not tested Option 2 but have seen reports that it also works. Make sure to read the prerequisites here: http://support.microsoft.com/kb/2637518
Option 1: Uninstall the patch and reboot the server. A quicker way to find out if the server is having this issue is to try deleting a message in OWA, or checking for repeated Application Error logs for Event ID 3
Once KB2756920 is uninstalled rerun the patch scan (it will show up as missing) and set to ignore. To set a patch to Ignore click on “Machines” and check the box to the left on a machine then click “Set Ignore” at the top of the page. The patch will no longer be scheduled installation on those machines when Automatic Update occurs.
Option 2: Install Hotfix for Microsoft .NET Framework 3.5.1 on Windows 7 RTM and Windows Server 2008 R2 RTM
https://www.microsoft.com/en-us/download/details.aspx?id=28949
Some of the Exchange 2010 symptoms include:
1. No free/busy information for meeting requests in Outlook
2. Cannot access the Out Of Office Assistant from Outlook
3. “MailTips could not be retrieved” message above the To: line when opening a new message in Outlook
4. In OWA if you try to attach a file to an email message, it says:”The action you tried to perform couldn’t be completed because there’s a configuration problem on the server. If the problem continues, contact your helpdesk.”
5. In OWA if you try to delete an email it says: “An unexpected error occurred and your request couldn’t be handled.” Users cannot move items between folders or delete emails in OWA
6. Autodiscovery fails; hence all processes that are dependent on this will fail as well.
Please let us know if you discover any other symptoms/fixes.
Special thanks to VA Support guru Jim Bulger and the Network Depot Tech team for feedback!