> The server that works, that's where the NFS share is mounted. The workstation
> that fails, it uses the mounted NFS share from the server that works.

You mean the server that works is where the NFS share is mounted *from* - so for
the server, this is a local filesystem, while for the workstation, it's a
remotely mounted NFS file system, right?

> cat session.log
> Error: Aborting session with 'Unable to open display
> 'nx/nx,options=/tmp/.x2go-localguy/C-localguy-137-1509136412_stDXFCE_dp32/options:137''.

Well, interesting. Is this file still available? If yes, what is its content?

Also, if available, the "clients" file would be interesting.

drwx------ 2 localguy localguy   40 Oct 27 16:33 cache-unix-kde-depth_32

drwx------ 2 localguy localguy   60 Oct 27 16:33 C-localguy-137-1509136412_stDXFCE_dp32

-rw-rw-r-- 1 localguy localguy   53 Oct 27 16:33 cmdoutput

-rw-rw-r-- 1 localguy localguy  500 Oct 27 16:33 options

-rw------- 1 localguy localguy 1841 Oct 27 16:33 session.log

-rw-rw-r-- 1 localguy localguy   11 Oct 27 16:33 sshd.pid