Directory Synchronization can not be stopped or started, rebooting the QMM console does not resolve the issue.
This can happen if one of the involved computers (eg. DSA ) was rebooted or connectivity was lost for a short period of time.
On the computer where DSA is installed find and stop all the Quest services using the Windows services snapin.
After approx. 1 minute start all the Quest services
Using the QMM console (the GUI) try to stop and start the synchronization.
If this does not resolve your issue, please attempt the procedure again before contacting Quest Support.
For more information and alternative procedures please review the video in SOL93861.
The steps from the SOL93861 should be tried as last resort, only after contacting support (via support ticket) and after creating a backup of the adam database.