On 03/26/2018 03:53 PM, Mihai Moldovan wrote:
Please make sure that nx-libs 3.5.99.16 is installed on the server side.
This sounds like a typical incarnation of the DPMS bug, fixed with nx-libs 3.5.99.15.

thanks Mihai


I confirm that the server giving the first error, i.e. "The remote proxy closed the connection while negotiating ..."
has indeed installed an older version of libnx-x11 (3.5.0.33~710).

after letting apt-get to upgrade the nx libraries and x2go packages,
I saw the libnx-x11 was replaced by a new package named libnx-x11-6, and
the version is now 3.5.99.16. However, now I start seeing the 2nd error
message on those machines, i.e. "connection failed".

However, this doesn't sound like it. Normally the DPMS bug only manifests after
a pretty long time (say, an hour or 1.5h, depending on DPMS settings), but not
right away after starting the session. I haven't yet seen such an error message
yet. It's possible that it's caused by the session repositioning on non-first
displays/nxagent crashing bug as fixed with nx-libs 3.5.99.16, but normally that
incarnates differently (i.e., nxagent is being started successfully, but then
dies quickly while starting the session without a client-side error message).

here is a dump of the session.log file under the failed session:


NXAGENT - Version 3.5.99.16

Copyright (c) 2001, 2011 NoMachine (http://www.nomachine.com)
....
See https://github.com/ArcticaProject/nx-libs for more information.

Info: Agent running with pid '17844'.
Session: Starting session at 'Mon Mar 26 16:56:11 2018'.
Error: Aborting session with 'Unable to open display 'nx/nx,options=/tmp/.x2go-fangq/C-fangq-50-1522097770_stDXFCE_dp24/options:50''.
Session: Aborting session at 'Mon Mar 26 16:56:11 2018'.
Session: Session aborted at 'Mon Mar 26 16:56:11 2018'.



strangely, the x2go window reports something differently, it says (see attached screenshot)

"PANIC!" Failure negotiating the session in stage 7
...
Wrong version or invalid session authentication cookie.
....


are these two error messages caused by a single issue or multiple?

I've already restarted x2gosever, but no dice. any other files that I need to reset/clear?

thanks

Qianqian




Mihai