I am getting the following message frequently when trying to open DSM Explorer:
"The AM Manager does not respond. Please check if the AM Manager is running."
Client Automation - All versions
Although there are many possible causes for this error to occur, one of the most likely ones is a short timeout for the Admin Console.
Increase the Admin Console timeout.
Update the default configuration policy or create a new one, seal it and publish it.
The policy value to change is:
/Domain/Control Panel/Configuration/Configuration Policy/<>/DSM/Administration Console/Session Messaging Timeout
Increase it to 600 and try if the problem persists.