Getting the exact same thing here from two situations:
Fedora 20 x64 -> Win 7 x64
Win 8 x64 -> the same Win 7 x64
And in the Win 7 server logs, I can find those lines each time I’m trying to connect :
2014-03-20 23:05:54 747.712 NXSERVER-4.1.29[2648] User ‘camino\pperron’ logged in from ‘10.0.252.240’.
2014-03-20 23:05:56 809.063 NXSERVER-4.1.29[2648] ERROR: Cannot connect to node.
2014-03-20 23:05:56 810.560 NXSERVER-4.1.29[2648] ERROR: No available displays found.