After updating x2goserver and x2goserver-xsession on CentOS 7, the x2go client can no longer maintain a x2go session with the x2go server; that is, client connects, a black screen with the X2GO logo is displayed, and the session is terminated. A full system update was done which also included updates for installed x2go packages. If the previous x2goserver and x2goserver-xsession packages are re-installed, everything works as expected. The client and server software details are listed below.
Loop: WARNING! Unrecognized session type 'unix-kde-depth_32'. Assuming agent session.
Auth: WARNING! Failed to read data from the X auth command.
Auth: WARNING! Generating a fake cookie for X authentication.
Loop: WARNING! Could not retrieve the X server authentication cookie.
running as X2Go Agent
NXAGENT - Version 3.5.0
Copyright (C) 2001, 2011 NoMachine.
Info: Agent running with pid '10668'.
Session: Starting session at 'Fri Dec 12 01:26:16 2014'.
Info: Proxy running in server mode with pid '10668'.
Info: Waiting for connection from 'localhost' on port '30021'.
Info: Accepted connection from '127.0.0.1'.
Info: Connection with remote proxy completed.
Info: Using ADSL link parameters 512/24/1/0.
Info: Using agent parameters 5000/10/50/0/0.
Info: Using cache parameters 4/4096KB/8192KB/8192KB.
Info: Using pack method '16m-jpeg-9' with session 'unix-kde-depth_32'.
Info: Using ZLIB data compression 1/1/32.
Info: Using ZLIB stream compression 4/4.
Info: No suitable cache file found.
Info: Listening to X11 connections on display ':56'.
Info: Established X client connection.
Info: Using shared memory parameters 1/1/0/0K.
Info: Using alpha channel in render extension.
Info: Not using local device configuration changes.
keyboard file created
Session: Session started at 'Fri Dec 12 01:26:26 2014'.
Session: Terminating session at 'Fri Dec 12 01:26:27 2014'.
Info: Waiting the cleanup timeout to complete.
Session: Session terminated at 'Fri Dec 12 01:26:27 2014'.
FD#4 channel ID#1.