The error indicates that the Wowza Media Server is not able to make a TCP connection to the Wowza Media Server on the other side. So it is some sort of TCP port 1935 communication problem. I would focus your attention there to start.
Are you connecting from the same machine that is running Wowza Media Server? Is there any other firewall or protection getting in the way? There could be something on their end that is blocking the connection but I have no idea how or why.