Unfortunately on one of our servers this update was applied.

The effect - after several manual adaptations - now is, that iManager is unusable on that server, due to a java version mismatch with the eclipse packet used by iManager.

But, if you have umc-server installed and running on any server first look into /etc/ssl/servercerts, if the elliptic curve certificate serverECcert.pem and key serverECkey.pem are present there. Out of three servers only one (which was freshly installed as OES 2023) had those in this place, despite the fact, that all servers have those server certificates in eDirectory.

OES 24.1.1 adds the redis@umc.service to the umc-server and this relies only on these EC certificates. You can change the certificates used in the configuration file, but -  these certificates are hard coded in the startup and config script for umc-server instead of taking the values of the configuration file and use those, which would give users the possibility to exchange certificates easily. This type of scripting is typically for test and preliminary uses, which seem to be the new OT standard for software releases.

You can quite easily put the needed certificate and key in this place - but I doubt, that those will be updated, if you update your server certificates.

And since this update iManager opens with an empty page and novell-tomcat shows the following errors:

SEVERE [ajp-nio-127.0.0.1-9009-exec-4] org.apache.catalina.core.ApplicationDispatcher.invoke Servlet.service() for servlet [jsp] threw exception

java.lang.UnsupportedClassVersionError: JVMCFRE199E bad major version 55.0 of class=org/eclipse/jdt/internal/compiler/env/INameEnvironment, the maximum supported major version is 52.0; offset=6
.....

Same here. How to fix it?

Where do I get this serverECkey.pem certificate?

by generating certificates with imanager on server objects!

the files can be found on /etc/ssl/servercerts/serverECkey.pem, serverECcert.pem, servercert.pem, serverkey.pem 

But take a look before on the place from this certificates and the symbolic links! I had false or older sym links, that i must replace manually

you can configure umc with yast2 umc or yast umc, verify this before generating new certificates...

by generating certificates with imanager on server objects!

the files can be found on /etc/ssl/servercerts/serverECkey.pem, serverECcert.pem, servercert.pem, serverkey.pem 

But take a look before on the place from this certificates and the symbolic links! I had false or older sym links, that i must replace manually

you can configure umc with yast2 umc or yast umc, verify this before generating new certificates...