The following error occurs while trying to open the DSM Explorer either on a remote machine or directly on the server:
Connection to server closed: Connection timed-out or server stopped (or, less probable, network problem) [SDM000021]
In SQL Server, set the option on database to 'AUTO GROW enabled' for Data & log file.
Grant the 'Administrator' group Full Control permissions on the Object Class "Manager".
You can also increase the 'SMtimeout' of the console via the following policy on the Domain Manager:
Control Panel->Configuration->Configuration Policy->Default Computer Policy->DSM->Admin Console->Session Messaging timeout.
Set this to 600.