Unfortunately a well-known topic, there are several threads about it here in the forum
first approach the matter with the systemctl, the cli command knows some important options and parameters here is something to look at what I have artificially created in the lab

systemctl list-units --state failed
  UNIT                         LOAD   ACTIVE SUB    DESCRIPTION
● oes-cis-agent.service        loaded failed failed CIS agent for OES
● oes-cis-recall-agent.service loaded failed failed CIS recall agent for OES
● oes-cis-scanner.service      loaded failed failed CIS scanner for OES
● oes-dashboard-agent.service  loaded failed failed Dashboard agent for OES

LOAD   = Reflects whether the unit definition was properly loaded.
ACTIVE = The high-level unit activation state, i.e. generalization of SUB.
SUB    = The low-level unit activation state, values depend on unit type.
4 loaded units listed.

systemctl list-units | grep -i failed

systemctl list-units --state failed

for oes-cis-agent.service

 systemctl status oes-cis-agent.service

further approaches can then be seen

Although no CIS is configured on the test system, it can be started and the

ssystemctl status oes-cis-agent.service
● oes-cis-agent.service - CIS agent for OES
     Loaded: loaded (/usr/lib/systemd/system/oes-cis-agent.service; enabled; vendor preset: disabled)
     Active: active (running) since Fri 2024-08-16 15:17:38 CEST; 1s ago
       Docs: www.microfocus.com/.../
   Main PID: 26935 (cisagents)
      Tasks: 5
     CGroup: /system.slice/oes-cis-agent.service
             └─ 26935 /opt/novell/cis/bin/cisagents -njob=10 -nfile=25 -nchunk=100 -maxprocs=0 -capabilities=differentialScan,migration,dryRun -two-pass-migration>

Aug 16 15:17:38 thor systemd[1]: Started CIS agent for OES.

the analysis continues by viewing the service start script

cat /usr/lib/systemd/system/oes-cis-agent.service
[Unit]
Documentation=www.microfocus.com/.../
Description=CIS agent for OES
After=oes-cis-recall-agent.service
Wants=network-online.target oes-cis-recall-agent.service oes-core-agent.service

[Service]
Environment="LD_LIBRARY_PATH=/usr/lib64/"
EnvironmentFile=-/etc/opt/novell/cisagent/config
ExecStart=/opt/novell/cis/bin/cisagents -njob=${NJOB} -nfile=${NFILE} -nchunk=${NCHUNK} -maxprocs=${MAXPROCS} -capabilities=${CAPABILITIES} -two-pass-migration=${TWO_PASS_MIGRATION}
Restart=on-abort
RestartPreventExitStatus=32
#LimitNOFILE=${CIS_AGENT_OPEN_FILES_LIMIT}

[Install]
WantedBy=multi-user.target

In the Start Script file you will find further information to go deeper into the analysis.

In this case, you have to search for the error in x-windows and gnome. My example can be transferred, the small approach is part of a LINUX system analysis which is normally done by 1,5 Level or Backlinerer.

/opt/novell/oes-install/uti/ oes_upgrade_check.pl

is one of the tools that must be carried out before a migration, e.g. from 2018 to 23.x as tip

Please search in the post about migration to oes 23 and 23.4

George

Is the server also running GroupWise? If so there are some incompatible libraries that stop X loading. There is a LONG thread on here with how to fix the library links.

Here is the thread community.microfocus.com/.../gathering-oes23-4-in-place-upgrade-issues-and-their-solutions

Yes, it is running GroupWise. I will do it and repost as soon as I finish this fix

I confess that after reading some documents I don´t know where to start my troubleshooting. I am considering new strategies and what I am going to try is installing a brand new OES with 23.4 DVD media, install GroupWise and then do the UPGRADE to check if everything runs smoothly.
Actually I have alredy done the installation of OES and Groupwise and everything is fine. I will now update OES to check if there is any other problem.

I finish my test and it was not good, let me report what happened:
1- I installed a brand new OES234 with DVD ISO with NSS and iPrint. cat /etc/novell-release showed 2023.1 = 23.4
2- I installed a brand new groupwise (for testing only) and it was good I created 2 users and it was all right
3- I rebooted this system and groupwise was fine and graphical interface too
4- I registered it and I gave a zypper up on system console, after that system was showing OES 24.3
5- I rebboted the system and graphical interface was dead, same error

So I can see that we can install OES234 and GroupWise 24.3 with no problem, but after that I could not UPDATE OES and have the system healthly.

I have already open a CASE in Support Portal

===============================================
A remote session was done and the answer was at KM000025041, follow this TID and the problem will be solved

Is the test system still alive? If so, please run the output of systemctl list-units --state failed.