When attempting to edit a graphic on an ES or AS the Graphics Editor reports it has lost connection.
A second instance of the workstation is running on the same computer
The firewall is blocking the connection.
If you use Remote Desktop (RDP) to access the ES remotely a second instance of the workstation could be initiated.
Close the workstation on both the remote connection and at the ES.
Then open the workstation either at the ES or via remote connection, not both.
Check if the firewall has been enabled while logged in to the ES or AS, and disable the firewall
Here is an example for McAfee
Make sure the network information (such as gateway) for the PC is entered correctly.