CMK version: 2.4.18 raw
OS version: Ubuntu 25.04
Error message: journalctl: /omd/sites/XXX/lib/libcrypto.so.3: version OPENSSL_3.4.0' not found (required by /usr/lib/x86_64-linux-gnu/systemd/libsystemd-shared-257.so
Ubuntu 25.04 works with openssl 3.4 while omd libs are in openssl version 3.0
RRDCACHED doesn’t work
others parts are ok.
There is no CheckMK build available for 25.04, I think you need to wait for the next LTS 26.04 before you can upgrade your 24.04 CMK instances.
So checkmk will be available/ready for LTS 26.04 ?
Sometime in the future after the release of 26.04. Normally you should plan for some time after the release. For the 24.04 release it was around two months after release that CheckMK builds where available. But for the last Debian it took longer as there where some problems with dependencies existing.