Event Log Error: Microsoft.ResourceManagement: System.Data: System.InvalidOperationException: The requested operation cannot be completed because the connection has been broken. at System.Data.SqlClient.SqlInternalConnectionTds.ExecuteTransaction
I had set up a clean environment some weeks ago, and just today I started configuring MA's. When I got to the FIM MA I wanted to do an import, sync and export, and when I got to the export it seemed to run endless. In the eventlog I got the same errors as you did.
Didn't find any real hints in SQL or in the FIM requests history... After doing a good old reboot it just started working...
I am getting this error as well. It appears for no particular reason (no change in configuration, no change in availability of SQL server) and it doesn't go away until FIM Service is restarted.
During that time, users do experience problems registering/resetting their passwords and accessing FIM portal.
Best of all, this problem occurs only in production... extremely annoying to say at least...