The below error may occur when creating or editing any GPO within GPOADmin:
System.ServiceModel.EndpointNotFoundException: Could not connect to net.tcp://servername.domain.com:50584/Public/Sdk. The connection attempt lasted for a time span of 00:00:02.0280390. TCP error code 10061: No connection could be made because the target machine actively refused it ::1:50584. ---> System.Net.Sockets.SocketException: No connection could be made because the target machine actively refused it
at System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress)
at System.Net.Sockets.Socket.Connect(EndPoint remoteEP)
at System.ServiceModel.Channels.SocketConnectionInitiator.Connect(Uri uri, TimeSpan timeout)
--- End of inner exception stack trace ---