MTA reports "OnProcessItem Error 13 Type mismatch" after installing hotfix 20120505EX (4281256)

After installing hotfix 20120505EX the Mail Target Agent may encounter the following error, and may not process PRV files.

5/8/2012 12:48:27 PM MTAApp::OnProcessItem Error 13 Type mismatch

5/8/2012 12:48:27 PM CADQueue::NextItem TraceMsg 4514 No more items to process in this session

A defect has been identified in this hotfix that causes this issue. The issue only happens when an agent host with an existing MTA is upgraded using the "hotfix installation wizard".

To workaround this issue, uninstall the Mail Target Agent and Shared Components from the agent host. Make sure the following folders are deleted:

32 Bit:

C:\program files\common files\aelita shared\

C:\windows\system32\aelita exchange migration wizard\Mail Target Agent\

64 Bit:

C:\program files (x86)\common files\aelita shared\

C:\windows\syswow64\aelita exchange migration wizard\Mail Target Agent\

Reboot the host if prompted by the uninstall process.

Then re-install the Mail Target Agent and Shared Components using the "Install/Uninstall Agents" wizard in the QMM console.

A new hotfix will be released shortly to address this issue.