Hi,

I use x2go successfully for several years and I very like it, thank you!

I have a problem with the latest x2go (http://ppa.launchpad.net/x2go/stable/ubuntu xenial main).

I can login without problem to the server, working as expected, but when I do not work on the x2go session (inactive or idle), the server closes the connection and it is not possible to connect again. 

Before the upgrade I had open sessions for days.

Any idea? Below the technical details.

The client debug shows (short version): 

x2go-DEBUG-../src/sshmasterconnection.cpp:2089> Forwarding parameters: from remote ("localhost":49454) to local ("localhost":49788)

x2go-DEBUG-../src/sshmasterconnection.cpp:2126> Temporary session port after config file parse: 49454

x2go-DEBUG-../src/sshmasterconnection.cpp:2130> Temporary session host after config file parse: localhost

x2go-DEBUG-../src/sshmasterconnection.cpp:2160> New channel forwarded.

x2go-DEBUG-../src/sshmasterconnection.cpp:2320> "ssh_channel_write failed": "Remote channel is closed"

x2go-DEBUG-../src/sshprocess.cpp:472> I/O error: "ssh_channel_write failed."" - Remote channel is closed" (2).

x2go-DEBUG-../src/sshmasterconnection.cpp:2363> EOF sent.

x2go-DEBUG-../src/sshmasterconnection.cpp:2367> Channel closed.

x2go-DEBUG-../src/onmainwindow.cpp:6459> Proxy wrote on stderr: "Loop: PANIC! The remote NX proxy closed the connection.

Error: The remote NX proxy closed the connection.

"

x2go-DEBUG-../src/onmainwindow.cpp:6459> Proxy wrote on stderr: "Loop: PANIC! Failure negotiating the session in stage '7'.

Error: Failure negotiating the session in stage '7'.

Loop: PANIC! Wrong version or invalid session authentication cookie.

Error: Wrong version or invalid session authentication cookie.

So, on the server side the port 49454 did not exist and even on the server I can see the session running (with ps ax), it is not possible to connect (The remote NX proxy closed the connection....))

I did not find fresh or relevant information on the net, I spent about 2 days to figure out, but without success (purge, reinstall, xsession removing etc. - all done, without results)

On the server, the sshd log contains this relevant information (it is the pair of the client debug log above):

Mar  5 19:45:11 localhost sshd[19999]: Accepted publickey for xxxx from YYYYY.98 port 43002 ssh2: RSA SHA256:notrelevant

Mar  5 19:45:11 localhost sshd[19999]: pam_unix(sshd:session): session opened for user username by (uid=0)

Mar  5 19:45:11 localhost systemd-logind[787]: New session 9 of user username.

Mar  5 19:45:22 localhost su[20438]: Successful su for username by root

Mar  5 19:45:22 localhost su[20438]: + ??? root:username

Mar  5 19:45:22 localhost su[20438]: pam_unix(su:session): session opened for user username by (uid=0)

Mar  5 19:45:22 localhost systemd-logind[787]: New session c1 of user username.

Mar  5 19:45:22 localhost su[20438]: pam_unix(su:session): session closed for user username

Mar  5 19:45:22 localhost su[20492]: Successful su for username by root

Mar  5 19:45:22 localhost systemd-logind[787]: Removed session c1.

Mar  5 19:45:22 localhost su[20492]: + ??? root:username

Mar  5 19:45:22 localhost su[20492]: pam_unix(su:session): session opened for user username by (uid=0)

Mar  5 19:45:22 localhost systemd-logind[787]: New session c2 of user username.

Mar  5 19:45:24 localhost su[20492]: pam_unix(su:session): session closed for user username

Mar  5 19:45:24 localhost systemd-logind[787]: Removed session c2.

Mar  5 19:45:25 localhost sshd[3615]: pam_unix(sshd:session): session closed for user username

Mar  5 19:45:29 localhost sshd[20011]: error: connect_to localhost port 49454: failed.

Mar  5 19:45:29 localhost sshd[20011]: channel_by_id: 0: bad id: channel free

Mar  5 19:45:29 localhost sshd[20011]: Disconnecting: Received ieof for nonexistent channel 0.

Mar  5 19:45:29 localhost sshd[19999]: pam_unix(sshd:session): session closed for user username

Mar  5 19:45:29 localhost systemd-logind[787]: Removed session 9.

The x2go server log from the syslog:

Here is the session opened first time, successfully, you can see the agent port (49454):

Mar  5 18:31:11 localhost /usr/bin/x2gostartagent: creating new session: username-50-1520271069_stDMATE_dp24 2a3a4f78ebac6c1318558ebfebbffff1 3799 YYYY.98 49454 49455 49456 -1 -1

In the syslog I did not find any related information about nxagent closing, but only the unsuccessful reconnect after 1 hour and 14 minutes. First reconnect, I was able to see the session selector window and I saw the session as running state, but I had only Suspend and Terminate buttons active. I pushed the suspend and resume, problem occurred.

Here are the packages on the server:

ii  cups-x2go                                    3.0.1.3-1                                    all          Virtual X2Go printer for CUPS

ii  libx2go-log-perl                             4.1.0.0-0~1517~ubuntu16.04.1                 all          Perl X2Go::Log package

ii  libx2go-server-db-perl                       4.1.0.0-0~1517~ubuntu16.04.1                 i386         Perl X2Go::Server:DB package

ii  libx2go-server-perl                          4.1.0.0-0~1517~ubuntu16.04.1                 all          Perl X2Go::Server package

rc  x2goagent                                    2:3.5.0.33-0~710~ubuntu16.04.1               all          X2Go agent

rc  x2godesktopsharing                           3.1.1.4-0~186~ubuntu16.04.1                  i386         Share X11 desktops with other users via X2Go

ii  x2gomatebindings                             0.0.1.5-0~203~ubuntu16.04.1                  i386         X2Go MATE bindings and MIME types

ii  x2goserver                                   4.1.0.0-0~1517~ubuntu16.04.1                 i386         X2Go server daemon scripts

ii  x2goserver-common                            4.1.0.0-0~1517~ubuntu16.04.1                 i386         X2Go Server (common files)

ii  x2goserver-extensions                        4.1.0.0-0~1517~ubuntu16.04.1                 all          X2Go Server (extension support)

ii  x2goserver-printing                          4.1.0.0-0~1517~ubuntu16.04.1                 all          X2Go server (printing support)

ii  x2goserver-x2goagent                         4.1.0.0-0~1517~ubuntu16.04.1                 all          X2Go Server's X2Go Agent

rc  x2goserver-xsession                          4.1.0.0-0~1517~ubuntu16.04.1                 all          X2Go Server (Xsession runner)

Here are the packages on the client:

ii  cups-x2go                                                   3.0.1.3-1                                        all          Virtual X2Go printer for CUPS

rc  x2goagent                                                   2:3.5.0.33-0~710~ubuntu16.04.1                   all          X2Go agent

ii  x2goclient                                                  4.1.1.1-0~1719~ubuntu16.04.1                     amd64        X2Go Client application (Qt4)

rc  x2gomatebindings                                            0.0.1.5-0~203~ubuntu16.04.1                      amd64        X2Go MATE bindings and MIME types

rc  x2goserver                                                  4.0.1.22-0~1197~ubuntu16.04.1                    amd64        X2Go server daemon scripts

rc  x2goserver-printing                                         4.0.1.22-0~1197~ubuntu16.04.1                    all          X2Go server daemon scripts (printing)

rc  x2goserver-xsession                                         4.0.1.22-0~1197~ubuntu16.04.1                    all          X2Go server daemon scripts (Xsession runner)

ii  x2gousbmount                                                1.1.0.2-0~469~ubuntu16.04.1                      all          clientside usb mass-storage device mounting