I installed WindowBuilder in Eclipse Oxygen.3a Release (4.7.3a) Build id: 20180405-1200 OS: Linux, v.4.15.0-20-generic, x86_64 / gtk 3.22.30 and getting an error:
Eclipse is running under 0, but this Java project has a 10 Java compliance level, so WindowBuilder will not be able to load classes from this project. Use a lower level of Java for the project, or run Eclipse using a newer Java version.
However, when I try to change project compliance I get a message:
Is it save to install multiple versions of JRE in Kubuntu 18.04? I thought I am running already Eclipse with newest Java version because I read this in my Configuration: