Exchange Provisioning Failure - Unresponsive Sync UI

I recently encountered an issue that had me baffled for several days.

This issue centered around Exchange provisioning via FIM and occurred with both 2007 and 2010. The short of the problem is that I was able to run completely through a synchronization cycle (DI,DS,EX) on both FIMMA and ADMA with provisioning turned off.  When Exchange provisioning was turned on the first export was run against the ADMA the Sync UI became totally unresponsive and locked up.  The only way to remedy the situation was to kill the miisserver.exe process and try again.

My first thought was to upgrade to the latest and greatest 4.1.3451.0. The latest hotfix also included a cumulative update introduced in 4.1.3441.0 which allowed the sync server to continue in the event of an Exchange provisioning failure. After patching all of the components in the lab up to the new version I found the issue was still present.

The really unusual part was that there were no failures in the event log of the sync server. Additionally, after looking at the log on the Exchange CAS server I was finding the command was executing without any failures!

While staring at add/remove programs contemplating rolling everything back to a previous version I noticed the WMF 3.0 framework (beta) and a light bulb went off. I immediately uninstalled WMF 3.0 beta and rebooted the server, as soon as it came back up provisioning was working.

Since I am huge fan of the new PowerShell 3.0 ISE, I had to go immediately download the WMF 3.0 RTM which did not cause any problems with Exchange provisioning.

As I have found many times, issues often jump out at you when you look somewhere completely different!