Hi, I am having the same problem too. I am working with a UR10 E-Series with V5.5.1.82186.
A have a Python-Daemon communicating with the URSCRIPTand within the daemon is also a RTDE communication running.
The error is difficult to reproduce. But all my test bring the same error after a couple of hours:
Runtime error (85:15): XMLRPCClient : Failed with exception: Unable to transport XML to server and get XML respose back. libcurl failed to execute the HTTP POST transaction explaining: Recv failure : Connection reset by peer.