Here is an explanation of some common error messages you may receive when attempting to establish a remote connection:
OM Server Not Available The MWExpertSystem and OMNetworkService services are not properly responding on Onsite Manager. Restart the services and attempt to connect again.
A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond. The target device has not been configured to accept incoming remote sessions from the Onsite Manager computer. Enable the remoting options on the target device and attempt to connect again.