License server fails to start after upgrade

I have been running a license server for MATLAB for many years - never had a problem before 2018b.

After installation of MATLAB 2018b, I shutdown the old license server and tried starting the new one - FAIL (confirmed with an echo $?).

Here is the core content of the service start/stop script:

MATLAB=/sw/matlab-2018b

case "$1" in

start)

if [ -f $MATLAB/etc/lmboot ]; then

$MATLAB/etc/lmboot -u sci-wam && echo 'MATLAB_lmgrd'

# /etc/lmboot_TMW -u sci-wam && echo 'MATLAB_lmgrd'

fi

;;

stop)

if [ -f $MATLAB/etc/lmdown ]; then

$MATLAB/etc/lmdown > /dev/null 2>&1

# /etc/lmdown_TMW > /dev/null 2>&1

fi

;;

*)

echo "Usage: $0 {start|stop}"

exit 1

;;

esac

If I set "MATLAB=/sw/matlab-2018a", the license server starts. The "-v" options talks about an "lmdebug.out" file, but none exists on the system. How do I go about diagnosing reason for failed service startup?

[Wayne Mallett]

I have made some progress on this. In previous versions of MATLAB, I've run the MLM daemon on a specific port by appending "port=<tcp_port>" to the license.dat line that starts with DAEMON MLM. Obviously, this is done to get traffic through a firewall which blocks all traffic to our server infrastructure by default (exceptions are configured). If I remove the "port=<tcp_port>" addition, the license service starts.

[Wayne Mallett]

I didn't work out how to troubleshoot the issue, however I have resolved it (I think) through a reboot. I'd still like to know why I could stop and start the license server for 2018a, but I couldn't stop the 2018a license server and start the 2018b license server (without a reboot).