We've seen that refreshing the services on the server should help. This is generally because a connection has been lost between the handheld and the server through TCP port 8123 so a refresh of the services should resolve that.
To do so navigate to services on your machine then stop and start ARMSV3 Service and ARMS.RemotingServer.
Stopping ARMSV3 first and ARMS.RemotingServer starting the services in reverse order.
Contact support team if the issue does not get resolved by above steps.