Here's an update. MATE still crashes.
rpm -q x2goserver
x2goserver-4.1.0.4-0.0x2go1.0.git20190329.1759.heuler.fc29.x86_64
May 15 09:07:05 ourserver /usr/bin/x2gostartagent[11784]: successfully started X2Go Agent session with ID ouruser-67-1557925622_stDMATE_dp32
May 15 09:07:06 ourserver /usr/bin/x2goruncommand[12242]: launching session with Xsession-x2go mechanism, using STARTUP="mate-session"
May 15 09:07:06 ourserver /usr/bin/x2goruncommand[12243]: dbus wrapper available as /usr/bin/dbus-run-session
May 15 09:07:12 ourserver gnome-keyring-daemon[12586]: couldn't access control socket: /run/user/1201/keyring/control: No such file or directory
May 15 09:07:12 ourserver mate-session[12246]: WARNING: keycode1 not existent
May 15 09:07:12 ourserver mate-session[12246]: WARNING: keycode2 not existent
May 15 09:07:16 ourserver systemd[1561]: Starting Sound Service...
May 15 09:07:16 ourserver dbus-daemon[908]: [system] Activating via systemd: service name='org.freedesktop.hostname1' unit='dbus-org.freedesktop.hostname1.service' requested by ':1.4752' (uid=1201 pid=12592 comm="/usr/libexec/mate-settings-daemon ")
May 15 09:07:16 ourserver systemd[1]: Starting Hostname Service...
May 15 09:07:17 ourserver dbus-daemon[908]: [system] Successfully activated service 'org.freedesktop.hostname1'
May 15 09:07:17 ourserver systemd[1]: Started Hostname Service.
May 15 09:07:19 ourserver kernel: traps: x2goagent[11774] trap divide error ip:55c9cc08ea1c sp:7ffe23323ec0 error:0 in nxagent[55c9cbfa0000+319000]
May 15 09:07:19 ourserver systemd[1]: Created slice system-systemd\x2dcoredump.slice.
May 15 09:07:19 ourserver systemd[1]: Started Process Core Dump (PID 12633/UID 0).
May 15 09:07:21 ourserver systemd-logind[1485]: Session 162 logged out. Waiting for processes to exit.
May 15 09:07:22 ourserver systemd-coredump[12634]: Process 11774 (x2goagent) of user 1201 dumped core.  Stack trace of thread 11774: 
#0  0x000055c9cc08ea1c XkbAdjustGroup (nxagent) 
#1  0x000055c9cc08eaf5 XkbComputeDerivedState (nxagent) 
#2  0x000055c9cc084ca6 ProcXkbLatchLockState (nxagent) 
#3  0x000055c9cbfc0d18 Dispatch (nxagent) 
#4  0x000055c9cbfa4821 main (nxagent) 
#5  0x00007f8cd60cd413 __libc_start_main (libc.so.6) 
#6  0x000055c9cbfa4b5e _start (nxagent)
May 15 09:07:25 ourserver abrt-server[12868]: Package 'nxagent' isn't signed with proper key
May 15 09:07:25 ourserver abrt-server[12868]: 'post-create' on '/var/spool/abrt/ccpp-2019-05-15-09:07:23.219326-11774' exited with 1
May 15 09:07:25 ourserver abrt-server[12868]: Deleting problem directory '/var/spool/abrt/ccpp-2019-05-15-09:07:23.219326-11774'
May 15 09:07:25 ourserver dbus-daemon[908]: [system] Rejected send message, 2 matched rules; type="method_call", sender=":1.4792" (uid=1201 pid=12613 comm="/usr/bin/pulseaudio --daemonize=no ") interface="org.freedesktop.DBus.ObjectManager" member="GetManagedObjects" error name="(unset)" requested_reply="0" destination="org.bluez" (bus)
May 15 09:07:26 ourserver systemd[1561]: Started Sound Service.
May 15 09:07:26 ourserver pulseaudio[12613]: E: [pulseaudio] bluez5-util.c: GetManagedObjects() failed: org.freedesktop.DBus.Error.AccessDenied: Rejected send message, 2 matched rules; type="method_call", sender=":1.4792" (uid=1201 pid=12613 comm="/usr/bin/pulseaudio --daemonize=no ") interface="org.freedesktop.DBus.ObjectManager" member="GetManagedObjects" error name="(unset)" requested_reply="0" destination="org.bluez" (bus)
May 15 09:07:32 ourserver systemd-logind[1485]: Removed session 162.
May 15 09:09:12 ourserver systemd-logind[1485]: New session 163 of user ouruser.
May 15 09:09:12 ourserver systemd[1]: Started Session 163 of user ouruser.
May 15 09:09:21 ourserver /usr/bin/x2gostartagent[13428]: successfully started X2Go Agent session with ID ouruser-78-1557925759_stDKDE_dp32
May 15 09:09:22 ourserver /usr/bin/x2goruncommand[13822]: ERROR: command  failed to execute
May 15 09:09:30 ourserver systemd-logind[1485]: Session 163 logged out. Waiting for processes to exit.
May 15 09:09:30 ourserver systemd-logind[1485]: Removed session 163.
May 15 09:10:13 ourserver systemd[1]: Starting system activity accounting tool...
May 15 09:10:13 ourserver systemd[1]: Started system activity accounting tool.
May 15 09:10:13 ourserver systemd-logind[1485]: New session 164 of user ouruser.
May 15 09:10:13 ourserver systemd[1]: Started Session 164 of user ouruser.
May 15 09:10:13 ourserver automount[1483]: add_host_addrs: hostname lookup for .cargo failed: No address associated with hostname
May 15 09:15:04 ourserver dbus-daemon[908]: [system] Activating via systemd: service name='net.reactivated.Fprint' unit='fprintd.service' requested by ':1.4832' (uid=0 pid=14472 comm="su - ")
May 15 09:15:04 ourserver systemd[1]: Starting Fingerprint Authentication Daemon...

gdb from the coredump:
Core was generated by `x2goagent -nolisten tcp -nolisten tcp -dpi 96 -D -auth /ouruser/.Xauthori'.
Program terminated with signal SIGFPE, Arithmetic exception.
#0  0x000055c9cc08ea1c in XkbAdjustGroup (group=<error reading variable: Division by zero>, ctrls=ctrls@entry=0x55c9cc8d1820) at xkbUtils.c:688
688     xkbUtils.c: No such file or directory.
(gdb) bt full
#0  0x000055c9cc08ea1c in XkbAdjustGroup (group=<error reading variable: Division by zero>, ctrls=ctrls@entry=0x55c9cc8d1820) at xkbUtils.c:688
        act = 0
#1  0x000055c9cc08eaf5 in XkbComputeDerivedState (xkbi=0x55c9cc8e6c20) at xkbUtils.c:714
        state = 0x55c9cc8e6c32
        ctrls = 0x55c9cc8d1820
        grp = <optimized out>
#2  0x000055c9cc084ca6 in ProcXkbLatchLockState (client=0x55c9ccc78500) at xkb.c:560
        status = <optimized out>
        dev = 0x55c9cc8b06c0
        oldState = {group = 0 '\000', locked_group = 0 '\000', base_group = 0, latched_group = 0, mods = 0 '\000', base_mods = 0 '\000', latched_mods = 0 '\000',
          locked_mods = 0 '\000', compat_state = 0 '\000', grab_mods = 0 '\000', compat_grab_mods = 0 '\000', lookup_mods = 0 '\000',
          compat_lookup_mods = 0 '\000', ptr_buttons = 0}
        newState = 0x55c9cc8e6c32
        changed = <optimized out>
        stuff = <optimized out>
#3  0x000055c9cbfc0d18 in Dispatch () at NXdispatch.c:482
        clientReady = 0x55c9cc8cc070
        result = <optimized out>
        client = 0x55c9ccc78500
        nready = <optimized out>
        icheck = 0x55c9cc3ef6d0 <checkForInput>
        start_tick = 0
        currentDispatch = <optimized out>
#4  0x000055c9cbfa4821 in main (argc=15, argv=0x7ffe23324118, envp=<optimized out>) at main.c:353
        i = <optimized out>
        xauthfile = <optimized out>
        alwaysCheckForInput = {0, 1}



On Wed, Mar 27, 2019 at 10:10 AM Robert Kudyba <rkudyba@fordham.edu> wrote:

On Tue, Mar 26, 2019 at 7:51 PM Robert Kudyba <rkudyba@fordham.edu> wrote:
> > c) you have configured a special keyboard configuration somewhere in Mate
> I don't recall doing so.  The only thing I did is allow the Hebrew
> keyboard (selectable in the menu bar), but I had used a Hebrew
> keyboard prior to this problem.

Ok, this sounds relevant. Can you please describe how this is set up?
and can you try if it works without that?

In the very top right of the screen there is a pull down menu, and Hebrew is available and unchecked.
 
> > d) you have configured caps lock/numlock being active on Mate startup
> > (I don't know if this is configurable in Mate)
> I haven't configured either of these for Mate.  In fact, I'd like to
> configure all keyboards to not use caps lock.  If you know a
> way to do this (so that caps lock is inactive for me, whether I'm on
> the console or elsewhere), please let me know.  Caps lock is an
> annoyance at best.

does this help? https://github.com/mate-desktop/mate-control-center/issues/29

> > e) you have caps lock/numlock activated on the x2go client side
> I have configured caps lock to be inactive on my Mac.  My Mac keyboard
> doesn't have a num lock key.

Ok, please also describe where you set this and retry with that
setting restored to the default.

The default setting is still there, it says Disabled. The screen shot from  github link is older and says Default. It appears to now say Disabled. Just to restate, "Caps Lock is Disabled" is NOT selected. And when we played with setting it, that option didn't make any difference, i.e., using Tweaks, when we chose  "Caps Lock is Disabled", caps lock still worked. The other radio button options at least did make a difference.

But it appears at least XFCE works and does not crash.