Cannot connect jRiver to serviio

In order to troubleshoot the problem I posted at http://forum.serviio.org/viewtopic.php?f=7&t=18268, I tried to connect jRiver (as UPnP renderer) with serviio and got the following error message:

I have attached a serviio debug log.
Anything I can do to fix this?
Thanks

I have attached a serviio debug log.
Anything I can do to fix this?
Thanks