Update from 4.4.9 to 5.x "postgresql94, old packages"

I try to update from 4.4.9 to 5.x but I got two messeages and therefore the update isnt possible. Please advice what will be the best way to solve this?

"Starting univention-upgrade. Current UCS version is 4.4-9 errata1272

Checking for package updates: none
Checking for app updates: none
Checking for release updates: found: UCS 5.0-0
Please rerun command without --check argument to install.
25.07.22 09:47:49.082 DEBUG_INIT
**** Starting univention-updater with parameter=[’/usr/share/univention-updater/univention-updater’, ‘net’, ‘–updateto’, ‘5.0-2’, ‘–ignoressh’, ‘–ignoreterm’]
starting net mode
—>DBG:update_available(mode=net, cdrom_mount_point=/media/cdrom, iso=None)
Checking network repository
Update to = 5.0-0
**** Downloading scripts at Mon Jul 25 09:47:55 2022
**** Starting actual update at Mon Jul 25 09:48:00 2022

Starting /tmp/tmpWzS47S/preupoigkMf.sh (Mo 25. Jul 09:48:00 CEST 2022):

Please check the release notes carefully BEFORE updating to UCS 5.0-0:
English version: UCS 5.0 Release Notes
German version: UCS 5.0 Release Notes

Please also consider documents of following release updates and
3rd party components.

Do you want to continue [Y/n]?
Custom preupdate script /var/lib/local-preup.sh not found
Checking adc_mapping … OK
Checking adc_multiinstance_mapping … OK
Checking architecture … OK
Checking blocking_apps … Unable to cache apps
Unable to cache apps
Checking default_master_packages … OK
Checking disk_space … OK
Checking failed_ldif … OK
Checking for_postgresql94 … FAIL
Checking hold_packages … OK
Checking kernel … OK
Checking kolab_schema … OK
Checking ldap_connection … OK
Checking ldap_schema … 62de4ace /etc/ldap/slapd.conf: line 164: rootdn is always granted unlimited privileges.
Checking legacy_objects … OK
Checking master_version … OK
Checking md5_signature_is_used … OK
Checking min_version … OK
Checking minimum_ucs_version_of_all_systems_in_domain … OK
Checking old_packages … FAIL
Checking overwritten_umc_templates … OK
Checking ox_schema … OK
Checking package_status … OK
Checking python_ucr_template_compatibility … OK
Checking python_ucsschool_hooks_compatibility … OK
Checking role_package_removed … OK
Checking samba_server_schannel … OK
Checking samba_tdb_size … OK
Checking sha1_signature_is_used … OK
Checking slapd_on_member … OK
Checking ssh … OK
Checking system_date_too_old … OK
Checking system_role … OK
Checking term … OK
Checking tls_public_key_size … OK
Checking tls_public_key_size_ucs-sso … OK
Checking ucsschool_computerroom_compatibility … OK
Checking usr_mountpoint … OK
Checking valid_machine_credentials … OK

The system can not be updated to UCS 5.0 due to the following reasons:

WARNING: PostgreSQL-9.4 is no longer supported by UCS-5.0 and must be migrated to
a newer version of PostgreSQL. See Updating from PostgreSQL 9.4 to PostgreSQL 9.6 for
more details.

This check can be disabled by setting the UCR variable 'update50/ignore_postgresql94' to 'yes'.
But be aware that this is not recommended!

WARNING: The following packages from UCS-4 are still installed, which are no longer supported with UCS-5:
univention-kde Mark KDE as manually installed “apt-mark manual kde-standard” to keep KDE

Use “univention-remove --purge” with the packages as following arguments to remove them

Error: Update aborted by pre-update script of release 5.0-0


WARNING: PostgreSQL-9.4 is no longer supported by UCS-5.0 and must be migrated to
a newer version of PostgreSQL. See Updating from PostgreSQL 9.4 to PostgreSQL 9.6 for
more details.

Did you follow the link describing how to update postgres?

Hello and thx. The link to Upgrade did work fully, I dont know what realy the commands doing but the system was update form 9.4 to. 9.6. I did perform all steps.

[ -f /usr/sbin/univention-pkgdb-scan ] && chmod -x /usr/sbin/univention-pkgdb-scan
service postgresql stop
rm -rf /etc/postgresql/9.6
apt-get install --reinstall postgresql-9.6
pg_dropcluster 9.6 main --stop
service postgresql start
test -e /var/lib/postgresql/9.6/main && mv /var/lib/postgresql/9.6/main /var/lib/postgresql/9.6/main.old
pg_upgradecluster 9.4 main
ucr commit /etc/postgresql/9.6/main/*
chown -R postgres:postgres /var/lib/postgresql/9.6
service postgresql restart
[ -f /usr/sbin/univention-pkgdb-scan ] && chmod +x /usr/sbin/univention-pkgdb-scan
univention-install --yes univention-postgresql-9.6
pg_dropcluster 9.4 main --stop
service postgresql restart
apt-get purge postgresql-9.4

After the upgrade I deleted the old packages by e.g.:
univention-remove --purge univention-kdm or univention-remove --purge univention-x-core

Now the system is up to date. Thx again for the hints. PS.: please performe every time backups between the steps this ensure an running system every time!!!