I'm using Netbeans to develop a Java application using JavaFX too.
When developing the application, I took the wrong decision to update my environment and went from Java8 to Java 11 and from Derby 10.14 to Derby 10.15. The result was that I understood that JavaFX support in the new environment was too complex for me and I upgraded my environment to Java8 and Derby 10.14.
Now, however, when I try to start the Java DB server, the following error appears: "java.lang.UnsupportedClassVersionError: org / apache / derby / drda / NetworkServerControl has been compiled by a newer version of the Java Runtime (class file version 53.0), this version of Java Runtime only recognizes versions of class files up to 52.0 "
I have searched in google, stackoverflow, etc. Without any result.
Sure, I understand that this is a problem of different versions, but how can I bring the NetworkServerControl to the version I'm using? Obviously, I do not want to update to Java9.