I had a problem with User Profile synchronisation not working any more. The service would be stuck ‘starting’ and I could not access the service page of the User Profile Service any more. A little investigation pointed me to an assembly problem; it was searching for Microsoft.ResourceManagement version 4.0.3531.2. I had no idea why.
I did install the october 2010 cumulative update, which was a faulty one when it was first released. I don’t know if this had anything to with it, but changed were made to the user profile config file. To correct these, follow these steps:
Open up Microsoft.ResourceManagement.Service.exe.config and go to the end of that file.
In my case, there were some illegal assembly binding redirects in the config file, which forced the executable to search for version 4.0.3531.2 of the assemblies. Comment out those lines.
Now restart the User Profile service and Sync service. This should work now.
After restarting the services; don’t forget to run an iisreset on your box when it also hosts Central Administration.
After these steps, all was working fine again. I have not a valid clue on what caused this, but at least it’s solved now 🙂