Hello, apologies, I found the relevant Wiki page on how to collect detailed logging info. I've grabbed data from multiple sources on the client and server, but haven't been able to interpret the log outputs to understand what the problem is.

Apologies for the data dump, but here are the relevant logs. Again, I've tried to replace most identifying info with variable names.


Last piece of output seen in x2go client GUI before crashing
---------------------------------------------------------------------

NXPROXY - Version 3.5.0

Copyright (C) 2001, 2010 NoMachine.
See http://www.nomachine.com/ for more information.

Info: Proxy running in client mode with pid '534'.
Session: Starting session at 'Tue $DATE 21:55:25 2016'.
Info: Connecting to remote host 'localhost:31001'.
Info: Connection to remote proxy 'localhost:31001' established.
Info: Connection with remote proxy completed.
Warning: Unrecognized session type 'unix-kde-depth_32'. Assuming agent session.
Warning: Failed to read data from the X auth command.
Warning: Generated a fake cookie for X authentication.
Info: Using MODEM link parameters 256/24/1/0.
Info: Using cache parameters 4/4096KB/8192KB/8192KB.
Info: Using pack method '4k-png-3' with session 'unix-kde-depth_32'.
InfoInfo: Established X server connection.
Info: Using shared memory parameters 0/0K.


Last bit of output from x2go server /var/log/auth.log
---------------------------------------------------------------------

$DATE $TIME $HOST sshd[14538]: reverse mapping checking getaddrinfo for $INTERNET_PROVIDER [$INTERNET_PROVIDER_IP] failed - POSSIBLE BREAK-IN ATTEMPT!
$DATE $TIME $HOST sshd[14538]: Accepted publickey for $USER from $INTERNET_PROVIDER_IP port 49488 ssh2: RSA $A_RSA_KEY
$DATE $TIME $HOST sshd[14538]: pam_unix(sshd:session): session opened for user $USER by (uid=0)
$DATE $TIME $HOST systemd-logind[1544]: New session 10 of user $USER.
$DATE $TIME $HOST su[15451]: Successful su for $USER by root
$DATE $TIME $HOST su[15451]: + ??? root:$USER
$DATE $TIME $HOST su[15451]: pam_unix(su:session): session opened for user $USER by (uid=0)
$DATE $TIME $HOST systemd-logind[1544]: New session c20 of user $USER.
$DATE $TIME $HOST su[15451]: pam_unix(su:session): session closed for user $USER
$DATE $TIME $HOST su[15468]: Successful su for $USER by root
$DATE $TIME $HOST su[15468]: + ??? root:$USER
$DATE $TIME $HOST su[15468]: pam_unix(su:session): session opened for user $USER by (uid=0)
$DATE $TIME $HOST systemd-logind[1544]: Removed session c20.
$DATE $TIME $HOST systemd-logind[1544]: New session c21 of user $USER.
$DATE $TIME $HOST sshd[14538]: pam_unix(sshd:session): session closed for user $USER
$DATE $TIME $HOST su[15468]: pam_unix(su:session): session closed for user $USER
$DATE 17:04:56 $HOST systemd-logind[1544]: Removed session c21.
$DATE 17:05:01 $HOST systemd-logind[1544]: Removed session 10.


Last bit of console output from x2go client run with the --debug flag
---------------------------------------------------------------------

x2go-DEBUG-../src/sshmasterconnection.cpp:1312> Locking SSH channel connection MUTEX.
x2go-DEBUG-../src/sshmasterconnection.cpp:1314> Passing new channel conenction object to channelConnections.
x2go-DEBUG-../src/sshmasterconnection.cpp:1316> Unlocking SSH channel connection MUTEX.
x2go-DEBUG-../src/onmainwindow.cpp:5995> Finished proxy.
x2go-DEBUG-../src/sshmasterconnection.cpp:1504> Creating new channel.
x2go-DEBUG-../src/sshmasterconnection.cpp:1508> New channel:0x7faa624f8a10
x2go-DEBUG-../src/sshmasterconnection.cpp:1539> Executing remote: "bash -l -c 'echo "X2GODATABEGIN:fa470e47-9c58-492b-879d-9beb33e7c7f6"; export PATH="/usr/local/bin:/usr/bin:/bin"; export TERM="dumb"; x2gocmdexitmessage $USER-50-1465337781_stDXFCE_dp32; echo "X2GODATAEND:fa470e47-9c58-492b-879d-9beb33e7c7f6";'"
Segmentation fault: 11

Relevant output from /var/log/syslog on x2go server:
---------------------------------------------------------------------

$DATE $TIME $HOST /usr/bin/x2golistsessions[4441]: x2golistsessions has been called with no option
$DATE $TIME $HOST /usr/bin/x2gostartagent: x2gostartagent called with options: 800x600 modem 4k-png unix-kde-depth_32 us query 0 D XFCE both
$DATE $TIME $HOST /usr/bin/x2gostartagent: client announced itself as ,,$IP_ADDRESS''
$DATE $TIME $HOST /usr/bin/x2gosessionlimit[4530]: x2gosessionlimit has been called
$DATE $TIME $HOST /usr/bin/x2golistsessions[4533]: x2golistsessions has been called with options: --all-servers
$DATE $TIME $HOST /usr/lib/x2go/x2gogetdisplays[4550]: db_getdisplays called, server: $HOST; return value:
$DATE $TIME $HOST /usr/lib/x2go/x2gogetports[4559]: db_getports called, server: $HOST; return value:
$DATE $TIME $HOST /usr/lib/x2go/x2goinsertsession[4589]: db_insertsession called, session ID: $USER-50-1465338404_stDXFCE_dp32, server: $HOST, session ID: $USER-50-1465338404_stDXFCE_dp32
$DATE $TIME $HOST /usr/lib/x2go/x2gogetports[4598]: db_getports called, server: $HOST; return value:
$DATE $TIME $HOST /usr/lib/x2go/x2goinsertport[4612]: db_insertport called, session ID: $USER-50-1465338404_stDXFCE_dp32, server: $HOST, SSH port: 30001
$DATE $TIME $HOST /usr/lib/x2go/x2gogetports[4621]: db_getports called, server: $HOST; return value: |30001|
$DATE $TIME $HOST /usr/lib/x2go/x2goinsertport[4635]: db_insertport called, session ID: $USER-50-1465338404_stDXFCE_dp32, server: $HOST, SSH port: 30002
$DATE $TIME $HOST /usr/lib/x2go/x2gogetports[4644]: db_getports called, server: $HOST; return value: |30001| |30002|
$DATE $TIME $HOST /usr/lib/x2go/x2goinsertport[4658]: db_insertport called, session ID: $USER-50-1465338404_stDXFCE_dp32, server: $HOST, SSH port: 30003
$DATE $TIME $HOST /usr/bin/x2gofeature: x2gofeature called with options: X2GO_RUN_EXTENSIONS
$DATE $TIME $HOST /usr/share/x2go/x2gofeature.d/x2goserver-extensions.features: x2goserver-extensions.features called with options: X2GO_RUN_EXTENSIONS
$DATE $TIME $HOST /usr/bin/x2goserver-run-extensions: x2goserver-run-extensions called with options: $USER-50-1465338404_stDXFCE_dp32 pre-start
$DATE $TIME $HOST /usr/bin/x2gostartagent: successfully started X2Go agent session with ID $USER-50-1465338404_stDXFCE_dp32
$DATE $TIME $HOST /usr/bin/x2gofeature: x2gofeature called with options: X2GO_RUN_EXTENSIONS
$DATE $TIME $HOST /usr/share/x2go/x2gofeature.d/x2goserver-extensions.features: x2goserver-extensions.features called with options: X2GO_RUN_EXTENSIONS
$DATE $TIME $HOST /usr/bin/x2goserver-run-extensions: x2goserver-run-extensions called with options: $USER-50-1465338404_stDXFCE_dp32 post-start
$DATE $TIME $HOST /usr/lib/x2go/x2gocreatesession[4737]: db_createsession called, session ID: $USER-50-1465338404_stDXFCE_dp32, cookie: 6daa3e6d71882d95ae1af583cc7db300, client: 194.75.11.7, pid: 4702, graphics port: 30001, sound port: 30002, file sharing port: 30003
$DATE $TIME $HOST /usr/bin/x2gostartagent: blocking creation of agent's keyboard file /tmp/.x2go-$USER/C-$USER-50-1465338404_stDXFCE_dp32/keyboard as requested by session startup command
$DATE $TIME $HOST /usr/bin/x2goruncommand: x2goruncommand called with options: 50 4702 $USER-50-1465338404_stDXFCE_dp32 30002 xfce4-session nosnd D
$DATE $TIME $HOST /usr/bin/x2goruncommand: exporting LD_LIBRARY_PATH=/usr/lib/nx/X11/Xinerama:/usr/lib/nx/X11
$DATE $TIME $HOST /usr/bin/x2gofeature: x2gofeature called with options: X2GO_RUN_EXTENSIONS
$DATE $TIME $HOST /usr/share/x2go/x2gofeature.d/x2goserver-extensions.features: x2goserver-extensions.features called with options: X2GO_RUN_EXTENSIONS
$DATE $TIME $HOST /usr/bin/x2goserver-run-extensions: x2goserver-run-extensions called with options: $USER-50-1465338404_stDXFCE_dp32 pre-runcommand
$DATE $TIME $HOST /usr/bin/x2goruncommand: running command /usr/bin/xfce4-session
$DATE $TIME $HOST /usr/bin/x2gomountdirs[4987]: x2gomountdirs has been called with options: dir $USER-50-1465338404_stDXFCE_dp32 $USER /home/$USER/.x2go/ssh/key.JL1025 /Users/$USER/.x2go/S-$USER-50-1465338404_stDXFCE_dp32/spool__PRINT_SPOOL___REVERSESSH_PORT__30003
$DATE $TIME $HOST /usr/bin/x2gomountdirs[4987]: mounting /tmp/.x2go-$USER/spool/C-$USER-50-1465338404_stDXFCE_dp32, mount point type is print spool directory
$DATE $TIME $HOST /usr/bin/x2gosetkeyboard: x2gosetkeyboard called with options:
$DATE $TIME $HOST /usr/bin/x2gofeature: x2gofeature called with options: X2GO_XSESSION
$DATE $TIME $HOST /usr/bin/x2gosetkeyboard: /home/$USER/.x2go/C-$USER-50-1465338404_stDXFCE_dp32/keyboard is blocked, not setting keyboard parameters from client-side settings
$DATE $TIME $HOST /usr/share/x2go/x2gofeature.d/x2goserver-extensions.features: x2goserver-extensions.features called with options: X2GO_XSESSION
$DATE $TIME $HOST /usr/bin/x2gomountdirs[4987]: db_insertmount called, session ID: $USER-50-1465338404_stDXFCE_dp32, path: /tmp/.x2go-$USER/spool/C-$USER-50-1465338404_stDXFCE_dp32, client: 127.0.0.1; return value: 1
$DATE $TIME $HOST /usr/bin/x2gomountdirs[4987]: SSH key file has arrived: /home/$USER/.x2go/ssh/key.JL1025
$DATE $TIME $HOST /usr/bin/x2gomountdirs[4987]: SSH host key has arrived: /home/$USER/.x2go/ssh/key.JL1025.ident
$DATE $TIME $HOST /usr/bin/x2gomountdirs[4987]: executing: timeout 30 sshfs  -o idmap=user,uid=`id -u`,gid=`id -g`,default_permissions,ServerAliveInterval=300,Cipher=blowfish,IdentityFile=/home/$USER/.x2go/ssh/key.JL1025,UserKnownHostsFile=/home/$USER/.x2go/ssh/key.JL1025.ident "$USER"@127.0.0.1:"/Users/$USER/.x2go/S-$USER-50-1465338404_stDXFCE_dp32/spool" "/tmp/.x2go-$USER/spool/C-$USER-50-1465338404_stDXFCE_dp32" -p 30003
$DATE $TIME $HOST /usr/share/x2go/x2gofeature.d/x2goserver.features: x2goserver.features called with options: X2GO_XSESSION
$DATE $TIME $HOST /usr/share/x2go/x2gofeature.d/x2goserver-lxdebindings.features: x2goserver-lxdebindings.features called with options: X2GO_XSESSION
$DATE $TIME $HOST /usr/share/x2go/x2gofeature.d/x2goserver-xsession.features: x2goserver-xsession.features called with options: X2GO_XSESSION
$DATE $TIME $HOST /usr/bin/x2goruncommand: launching session with Xsession-x2go mechanism, using STARTUP="xfce4-session"
$DATE $TIME $HOST /usr/bin/x2goruncommand: command /usr/bin/xfce4-session has finished
$DATE $TIME $HOST /usr/bin/x2gofeature: x2gofeature called with options: X2GO_RUN_EXTENSIONS
$DATE $TIME $HOST /usr/share/x2go/x2gofeature.d/x2goserver-extensions.features: x2goserver-extensions.features called with options: X2GO_RUN_EXTENSIONS
$DATE $TIME $HOST /usr/bin/x2goserver-run-extensions: x2goserver-run-extensions called with options: $USER-50-1465338404_stDXFCE_dp32 post-runcommand
$DATE $TIME $HOST /usr/bin/x2gofeature: x2gofeature called with options: X2GO_DESKTOPSHARING
$DATE $TIME $HOST /usr/share/x2go/x2gofeature.d/x2goserver-extensions.features: x2goserver-extensions.features called with options: X2GO_DESKTOPSHARING
$DATE $TIME $HOST /usr/share/x2go/x2gofeature.d/x2goserver.features: x2goserver.features called with options: X2GO_DESKTOPSHARING
$DATE $TIME $HOST /usr/share/x2go/x2gofeature.d/x2goserver-lxdebindings.features: x2goserver-lxdebindings.features called with options: X2GO_DESKTOPSHARING
$DATE $TIME $HOST /usr/share/x2go/x2gofeature.d/x2goserver-xsession.features: x2goserver-xsession.features called with options: X2GO_DESKTOPSHARING
$DATE $TIME $HOST /usr/lib/x2go/x2gochangestatus[5145]: db_changestatus called, session ID: $USER-50-1465338404_stDXFCE_dp32, new status: F
$DATE $TIME $HOST /usr/bin/x2goumount-session[5153]: x2goumount-session has been called with options: $USER-50-1465338404_stDXFCE_dp32
$DATE $TIME $HOST /usr/bin/x2goumount-session[5153]: db_getdisplay called, session ID: $USER-50-1465338404_stDXFCE_dp32; return value: 50
$DATE $TIME $HOST /usr/bin/x2goumount-session[5153]: db_getmounts called, session ID: $USER-50-1465338404_stDXFCE_dp32; return value: 127.0.0.1|/tmp/.x2go-$USER/spool/C-$USER-50-1465338404_stDXFCE_dp32|
$DATE $TIME $HOST /usr/bin/x2goumount-session[5153]: found mounted share $USER@127.0.0.1:/Users/$USER/.x2go/S-$USER-50-1465338404_stDXFCE_dp32/spool /tmp/.x2go-$USER/spool/C-$USER-50-1465338404_stDXFCE_dp32 fuse.sshfs rw,nosuid,nodev,default_permissions,user=$USER 0 0
$DATE $TIME $HOST /usr/bin/x2goumount-session[5153]: ERROR: failed to unmount "/tmp/.x2go-$USER/spool/C-$USER-50-1465338404_stDXFCE_dp32"
$DATE $TIME $HOST /usr/bin/x2gofeature: x2gofeature called with options: X2GO_FMBINDINGS
$DATE $TIME $HOST /usr/share/x2go/x2gofeature.d/x2goserver-extensions.features: x2goserver-extensions.features called with options: X2GO_FMBINDINGS
$DATE $TIME $HOST /usr/sbin/x2gocleansessions[1663]: $USER-50-1465338404_stDXFCE_dp32 is blocked
$DATE $TIME $HOST /usr/sbin/x2gocleansessions[1663]: $USER-50-1465338404_stDXFCE_dp32, pid 4702 cleaning up stale X11 socket file: /tmp/.X11-unix/X50
$DATE $TIME $HOST /usr/sbin/x2gocleansessions[1663]: $USER-50-1465338404_stDXFCE_dp32: unmounting all shares
$DATE $TIME $HOST /usr/share/x2go/x2gofeature.d/x2goserver.features: x2goserver.features called with options: X2GO_FMBINDINGS
$DATE $TIME $HOST /usr/share/x2go/x2gofeature.d/x2goserver-lxdebindings.features: x2goserver-lxdebindings.features called with options: X2GO_FMBINDINGS
$DATE $TIME $HOST /usr/share/x2go/x2gofeature.d/x2goserver-xsession.features: x2goserver-xsession.features called with options: X2GO_FMBINDINGS
$DATE $TIME $HOST /usr/bin/x2goumount-session[5212]: x2goumount-session has been called with options: $USER-50-1465338404_stDXFCE_dp32
$DATE $TIME $HOST /usr/bin/x2goumount-session[5153]: db_deletemount called, session ID: $USER-50-1465338404_stDXFCE_dp32, path: /tmp/.x2go-$USER/spool/C-$USER-50-1465338404_stDXFCE_dp32
$DATE $TIME $HOST /usr/bin/x2goumount-session[5212]: db_getdisplay called, session ID: $USER-50-1465338404_stDXFCE_dp32; return value: 50
$DATE $TIME $HOST /usr/bin/x2goumount-session[5212]: db_getmounts called, session ID: $USER-50-1465338404_stDXFCE_dp32; return value:
$DATE $TIME $HOST console-kit-daemon[3669]: GLib-CRITICAL: Source ID 35 was not found when attempting to remove it
$DATE $TIME $HOST /usr/lib/x2go/x2gormforward[5250]: Terminating SSHD process: 4406
$DATE $TIME $HOST console-kit-daemon[3669]: GLib-CRITICAL: Source ID 27 was not found when attempting to remove it
$DATE $TIME $HOST console-kit-daemon[3669]: GLib-CRITICAL: Source ID 46 was not found when attempting to remove it
$DATE $TIME $HOST /usr/lib/x2go/x2golistsessions_sql[5267]: dbsys_deletemounts called, session ID: $USER-50-1465338404_stDXFCE_dp32
$DATE $TIME $HOST /usr/lib/x2go/x2golistsessions_sql[5267]: Purging finished session from X2Go db, session ID: $USER-50-1465338404_stDXFCE_dp32
$DATE $TIME $HOST /usr/sbin/x2gocleansessions[1663]: $USER-50-1465338404_stDXFCE_dp32 is blocked
$DATE $TIME $HOST /usr/sbin/x2gocleansessions[1663]: $USER-50-1465338404_stDXFCE_dp32: unmounting all shares
$DATE $TIME $HOST /usr/bin/x2goumount-session[5287]: x2goumount-session has been called with options: $USER-50-1465338404_stDXFCE_dp32
$DATE $TIME $HOST /usr/bin/x2goumount-session[5287]: db_getdisplay called, session ID: $USER-50-1465338404_stDXFCE_dp32; return value:
$DATE $TIME $HOST /usr/bin/x2goumount-session[5287]: db_getmounts called, session ID: $USER-50-1465338404_stDXFCE_dp32; return value:
$DATE $TIME $HOST console-kit-daemon[3669]: GLib-CRITICAL: Source ID 61 was not found when attempting to remove it
$DATE $TIME $HOST console-kit-daemon[3669]: GLib-CRITICAL: Source ID 72 was not found when attempting to remove it
$DATE 18:27:30 $HOST /usr/bin/x2golistsessions[5504]: x2golistsessions has been called with no option
$DATE $TIME $HOST /usr/bin/x2gostartagent: x2gostartagent called with options: 800x600 modem 4k-png unix-kde-depth_32 us query 0 D XFCE both
$DATE $TIME $HOST /usr/bin/x2gostartagent: client announced itself as ,,194.75.11.7''
$DATE $TIME $HOST /usr/bin/x2gosessionlimit[5584]: x2gosessionlimit has been called
$DATE $TIME $HOST /usr/bin/x2golistsessions[5587]: x2golistsessions has been called with options: --all-servers
$DATE $TIME $HOST /usr/lib/x2go/x2gogetdisplays[5604]: db_getdisplays called, server: $HOST; return value:
$DATE $TIME $HOST /usr/lib/x2go/x2gogetports[5613]: db_getports called, server: $HOST; return value:
$DATE $TIME $HOST /usr/lib/x2go/x2goinsertsession[5642]: db_insertsession called, session ID: $USER-50-1465338455_stDXFCE_dp32, server: $HOST, session ID: $USER-50-1465338455_stDXFCE_dp32
$DATE $TIME $HOST /usr/lib/x2go/x2gogetports[5654]: db_getports called, server: $HOST; return value:
$DATE $TIME $HOST /usr/lib/x2go/x2goinsertport[5668]: db_insertport called, session ID: $USER-50-1465338455_stDXFCE_dp32, server: $HOST, SSH port: 30001
$DATE $TIME $HOST /usr/lib/x2go/x2gogetports[5677]: db_getports called, server: $HOST; return value: |30001|
$DATE $TIME $HOST /usr/lib/x2go/x2goinsertport[5691]: db_insertport called, session ID: $USER-50-1465338455_stDXFCE_dp32, server: $HOST, SSH port: 30002
$DATE $TIME $HOST /usr/lib/x2go/x2gogetports[5700]: db_getports called, server: $HOST; return value: |30001| |30002|
$DATE $TIME $HOST /usr/lib/x2go/x2goinsertport[5714]: db_insertport called, session ID: $USER-50-1465338455_stDXFCE_dp32, server: $HOST, SSH port: 30003
$DATE $TIME $HOST /usr/bin/x2gofeature: x2gofeature called with options: X2GO_RUN_EXTENSIONS
$DATE $TIME $HOST /usr/share/x2go/x2gofeature.d/x2goserver-extensions.features: x2goserver-extensions.features called with options: X2GO_RUN_EXTENSIONS
$DATE $TIME $HOST /usr/bin/x2goserver-run-extensions: x2goserver-run-extensions called with options: $USER-50-1465338455_stDXFCE_dp32 pre-start
$DATE $TIME $HOST /usr/bin/x2gostartagent: successfully started X2Go agent session with ID $USER-50-1465338455_stDXFCE_dp32
$DATE $TIME $HOST /usr/bin/x2gofeature: x2gofeature called with options: X2GO_RUN_EXTENSIONS
$DATE $TIME $HOST /usr/share/x2go/x2gofeature.d/x2goserver-extensions.features: x2goserver-extensions.features called with options: X2GO_RUN_EXTENSIONS
$DATE $TIME $HOST /usr/bin/x2goserver-run-extensions: x2goserver-run-extensions called with options: $USER-50-1465338455_stDXFCE_dp32 post-start
$DATE $TIME $HOST /usr/lib/x2go/x2gocreatesession[5790]: db_createsession called, session ID: $USER-50-1465338455_stDXFCE_dp32, cookie: d22102308606355627945a50fa7f6496, client: 194.75.11.7, pid: 5757, graphics port: 30001, sound port: 30002, file sharing port: 30003
$DATE $TIME $HOST /usr/bin/x2gostartagent: blocking creation of agent's keyboard file /tmp/.x2go-$USER/C-$USER-50-1465338455_stDXFCE_dp32/keyboard as requested by session startup command
$DATE $TIME $HOST console-kit-daemon[3669]: GLib-CRITICAL: Source ID 86 was not found when attempting to remove it
J

On Tue, Jun 7, 2016 at 10:13 PM, M.Rule <mrule7404@gmail.com> wrote:
We recently moved a server to a new network and x2go is not longer working. The x2go client crashes too quickly to view or copy the error messages that occur before it fails.

On the server side, I can see these messages in this in auth.log. I've replaced all possible identifying information (hopefully) with bash-style variable substituions (e.g. $USER). I apologize as this reduces clarity, but I don't want any identifiable details on record.

$DATE $TIME $HOSTNAME sshd[14538]: reverse mapping checking getaddrinfo for $INTERNET_PROVIDER [$INTERNET_PROVIDER_IP] failed - POSSIBLE BREAK-IN ATTEMPT!
$DATE $TIME $HOSTNAME sshd[14538]: Accepted publickey for $USER from $INTERNET_PROVIDER_IP port 49488 ssh2: RSA $A_RSA_KEY
$DATE $TIME $HOSTNAME sshd[14538]: pam_unix(sshd:session): session opened for user $USER by (uid=0)
$DATE $TIME $HOSTNAME systemd-logind[1544]: New session 10 of user $USER.
$DATE $TIME $HOSTNAME su[15451]: Successful su for $USER by root
$DATE $TIME $HOSTNAME su[15451]: + ??? root:$USER
$DATE $TIME $HOSTNAME su[15451]: pam_unix(su:session): session opened for user $USER by (uid=0)
$DATE $TIME $HOSTNAME systemd-logind[1544]: New session c20 of user $USER.
$DATE $TIME $HOSTNAME su[15451]: pam_unix(su:session): session closed for user $USER
$DATE $TIME $HOSTNAME su[15468]: Successful su for $USER by root
$DATE $TIME $HOSTNAME su[15468]: + ??? root:$USER
$DATE $TIME $HOSTNAME su[15468]: pam_unix(su:session): session opened for user $USER by (uid=0)
$DATE $TIME $HOSTNAME systemd-logind[1544]: Removed session c20.
$DATE $TIME $HOSTNAME systemd-logind[1544]: New session c21 of user $USER.
$DATE $TIME $HOSTNAME sshd[14538]: pam_unix(sshd:session): session closed for user $USER
$DATE $TIME $HOSTNAME su[15468]: pam_unix(su:session): session closed for user $USER
$DATE 17:04:56 $HOSTNAME systemd-logind[1544]: Removed session c21.
$DATE 17:05:01 $HOSTNAME systemd-logind[1544]: Removed session 10.

I'm not really familiar with things like this, but it looks like it is repeatedly creating new sessions, and then these sessions are closed (for some reason). I don't understand form these messages.

On the client side, this is as much of the log as I can get before the program crashes. I haven't been able to locate the x2go client logfiles .

NXPROXY - Version 3.5.0

Copyright (C) 2001, 2010 NoMachine.
See http://www.nomachine.com/ for more information.

Info: Proxy running in client mode with pid '534'.
Session: Starting session at 'Tue $DATE 21:55:25 2016'.
Info: Connecting to remote host 'localhost:31001'.
Info: Connection to remote proxy 'localhost:31001' established.
Info: Connection with remote proxy completed.
Warning: Unrecognized session type 'unix-kde-depth_32'. Assuming agent session.
Warning: Failed to read data from the X auth command.
Warning: Generated a fake cookie for X authentication.
Info: Using MODEM link parameters 256/24/1/0.
Info: Using cache parameters 4/4096KB/8192KB/8192KB.
Info: Using pack method '4k-png-3' with session 'unix-kde-depth_32'.
InfoInfo: Established X server connection.
Info: Using shared memory parameters 0/0K.

Can anyone help me debug this? I need more detailed errors if I'm going to solve this on my own -- I can't really access all the error messages, nor interpret the errors available, at the moment.

Thanks in advance if you're able to help.
Best,
M. Rule.