Recently, when I was trying to configure a User Profile Synchronization Connection in SharePoint 2010, I received the following error message when clicking the Populate Containers button.
Method not found: 'Int32 Microsoft.Office.Server.Administration.UserProfileApplicationProxy.get_LdapConnectionTimeout()'.
I double checked my credentials and tried again, but I received the same error message. After doing a ton of searching on the Internet, the results were pretty much inconclusive. When I looked at the current patch level of the SharePoint installation, I discovered it was on December 2010 CU. Having heard enough bad feedback about this particular cumulative update from others, I proceed to update to February 2011. I installed the update on each server and ran the configuration wizard. I then proceeded to try the Populate Containers button again. Sure enough, it worked this time. If you happen to receive this cryptic error message, try updating to a newer cumulative update to see if it resolves the issue.