Problems found with KB2756920 causing issues with SharePoint and Exchange 2010

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!