The customer is seeing some unusual activity on the OC server after a restart. e.g.
SPC-OCA-10301: Unable to write web.xml changes is returned trying to save/commit the changes after the OneClick SSO Configuration was configured and authentication successfully tested.
The catalina.out file showed the following exception:
Sep 24, 2018 12:43:19.651 - Error writing changes to web.xmljava.lang.Exception: SPC-OCA-10102: Error restarting the OneClick server: cannot set egid: Operation not permitted<br>SPC-OCA-10579: The user may not have permissions to use the 'at' command or to run the restart script. SPC-OCA-10594: <br>Please check the /etc/at.deny & /usr/Spectrum/tomcat/webapps/spectrum/configtomcat files.<br>
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
So the changes in web.xml was properly saved, but the user did not have permission to restart the OneClick server.
Customer rebooted the machine and verified that OC server was working properly, however due to other permission issues on that machine he rebuilt the server.
Note: some time after the OneClick installation OS updates were installed. More likely the the problem was with the underlying OS and not with OneClick.