I have not been successful at getting x2go to work consistently on
machines I have upgraded to Ubuntu 17.04, oddly it works on some and not
others. I have two machines on which it appears to work fine and two which it does not, one of those it just gives me a black screen and the other it
immediately exits. On the machine that it immediately exits it prints some
error messages but the client exits too fast to read them. I can't figure
out if and where x2go logs erros. I do see some things in the syslog but
indicates it is starting the session successfully when obviously it is not.

Have you seen this page on how to enable debug logging? http://wiki.x2go.org/doku.php/wiki:development:debugging

Other logging locations apart from the system's log are:

X2Go Server: /var/log/syslog
X2Go Client: stderr (use –debug)
PyHoca-GUI: stderr (use –libdebug –debug)
Xsession itself: $HOME/.xsession-x2go-errors
NX (server-side): $HOME/.x2go/C-<sessionid>/session.*
NX (client-side): $HOME/.x2go/S-<sessionid>/session.*

The default log levels for x2goserver and cups-x2go are set to notice. Available log levels are: emerg, crit, alert, err, warning, notice, info, debug.

The x2goserver log level can be set by editing:

root@x2goserver:~$ editor /etc/x2go/x2goserver.conf

Debugging X2Go Session Broker

The x2gobroker debug mode can be enabled in:

root@broker:~$ editor /etc/default/python-x2gobroker

The log files normally get written to /var/log/x2gobroker/*.log

You can also run

root@broker:~$ x2gobroker-daemon-debug

as user root. This is equivalent to running the broker daemon provided by the package x2gobroker-daemon, but you will see all output piped to stderr while the X2Go Session Broker daemon runs in foreground mode.