How to resolve the login error "Failed to connect to server."
The scm-server-0.log file reports HTTP 401 unauthorized.
IIS log shows status codes 401 3 64 and 404 0 64 when attempting to connect to the Endpoint Manager.
The Symantec Endpoint Protection Manager service is not listed in the IIS admin service restart dependency list.
Unresponsive IIS services will not allow the Endpoint Protection Manager service to stay started.
To reset unresponsive IIS services:
If connectivity with the Endpoint Protection Manager (SEPM) is not restored please refer to the document below or call Symantec Technical Support for further assistance.
Symantec Endpoint Protection Manager 11.x communication troubleshooting: