Problems with Java

[routeconverter]

Hello Christian!
OK, I installed both version, so I thought, but only one is active?.

No, since I'm using launch4j to search and launch the Java runtime it's a bit more complicated.
I've configured it like this:

• Prefer JRE over JDK
  
• Prefer 32 bits over 64 bits
  
• Minimum version: 8
  

It's not possible to be compatible with Java 8, and with Java 15 or later, but a lot of users install Java 17 since it's the latest LTS release. Since problems with that setup occur more frequently, I've added another configuration to the latest prerelease:

• Maximum version: 14
  

Do I have to uninstall the sdk 18 ( because sdk overwrites the sre ) or is there any possibility to switch to sre version 8? 

Please try the latest prelease. It should disregard your JDK 18 and use the JRE 8 on your machine – but I haven't tested that behaviour.