Compiling any JavaFX project in NetBeans returns Unsupported major.minor version 52.0

Question

I see a number of similar questions

• Netbeans 8.0 Unsupported major.minor version 52.0 error
• Unsupported major.minor version 52.0 Error (duplicate)
• Running a JAR I compiled: Unsupported major.minor version 52.0
• Can't fix Unsupported major.minor version 52.0 even after fixing compatibility

But none with the same circumstances as mine. I've tried their solutions anyway (when relevant) and they haven't helped.

I had created a JavaFX FXML Application in NetBeans 8.0.2 and had to manually upgrade the JDK from 1.7 to 1.8 to get features I wanted. I believe I was using 1.8.0_52 for both the JRE and the JDK and the project was compiling fine. Then my computer notified me of an update for Java 8. Now:

mc@MC-Desktop:~$ java -version
java version "1.8.0_60"
Java(TM) SE Runtime Environment (build 1.8.0_60-b27)
Java HotSpot(TM) 64-Bit Server VM (build 25.60-b23, mixed mode)

mc@MC-Desktop:~$ javac -version
javac 1.8.0_60

and suddenly any Java 8 FXML project gets the above error message during compile-time, even the standard basic JavaFX FXML Application that comes with NetBeans. Java 7 FXML will compile but 7 is missing important features. I've started new projects specifying 8 and I've started a new project in 7 and then upgraded it to 8: same result.

I've ensured that the Source/Binary Format is JDK 8, in the Sources category and the Java Platform is set to JDK 1.8 in the Libraries category of the project's properties. I can find no other setting to update. I've tried a clean build each time I change a setting. The error happens in an IDE-generated file jfx-impl.xml that is too large to post in its entirety, being over 4000 lines. I post a portion here. The classpath="${javafx.ant.classpath}" is line 406, where the compiler reports the error:

<target name="-check-ant-javafx-version" depends="-pre-check-ant-javafx-version,
        -set-endorsed-javafx-ant-classpath,-set-javafx-ant-classpath" if="do.check.ant-javafx.version">
    <echo message="ant-javafx.jar.location = ${ant-javafx.jar.location}" level="verbose"/>
    <echo message="javafx.ant.classpath = ${javafx.ant.classpath}" level="verbose"/>
    <taskdef resource="com/sun/javafx/tools/ant/antlib.xml"
        uri="javafx:com.sun.javafx.tools.ant"
        classpath="${javafx.ant.classpath}"/>
    <condition property="have-fx-ant-init">
        <typefound name="javafx:com.sun.javafx.tools.ant:init-ant"/>
    </condition>
    <property name="ant-javafx-version-already-checked-in-jfximpl" value="true"/>
    <echo message="have-fx-ant-init = ${have-fx-ant-init}" level="verbose"/>
</target>

The error message is:

/home/chris/Projects/Java/FXMLTimer/nbproject/jfx-impl.xml:3438: The following error occurred while executing this line:
/home/chris/Projects/Java/FXMLTimer/nbproject/jfx-impl.xml:406: 
java.lang.UnsupportedClassVersionError: com/sun/javafx/tools/ant/Permissions : Unsupported major.minor version 52.0
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
    at org.apache.tools.ant.AntClassLoader.defineClassFromData(AntClassLoader.java:1136)
    at org.apache.tools.ant.AntClassLoader.getClassFromStream(AntClassLoader.java:1307)
    at org.apache.tools.ant.AntClassLoader.findClassInComponents(AntClassLoader.java:1362)
    at org.apache.tools.ant.AntClassLoader.findClass(AntClassLoader.java:1323)
    at org.apache.tools.ant.AntClassLoader.loadClass(AntClassLoader.java:1076)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:278)
    at org.apache.tools.ant.taskdefs.Definer.addDefinition(Definer.java:579)
    at org.apache.tools.ant.taskdefs.Definer.execute(Definer.java:237)
    at org.apache.tools.ant.taskdefs.Antlib.execute(Antlib.java:180)
    at org.apache.tools.ant.taskdefs.Definer.loadAntlib(Definer.java:428)
    at org.apache.tools.ant.taskdefs.Definer.execute(Definer.java:277)
    at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:292)
    at sun.reflect.GeneratedMethodAccessor169.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
    at org.apache.tools.ant.Task.perform(Task.java:348)
    at org.apache.tools.ant.Target.execute(Target.java:435)
    at org.apache.tools.ant.Target.performTasks(Target.java:456)
    at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1393)
    at org.apache.tools.ant.helper.SingleCheckExecutor.executeTargets(SingleCheckExecutor.java:38)
    at org.apache.tools.ant.Project.executeTargets(Project.java:1248)
    at org.apache.tools.ant.taskdefs.Ant.execute(Ant.java:441)
    at org.apache.tools.ant.taskdefs.CallTarget.execute(CallTarget.java:105)
    at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:292)
    at sun.reflect.GeneratedMethodAccessor169.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
    at org.apache.tools.ant.Task.perform(Task.java:348)
    at org.apache.tools.ant.Target.execute(Target.java:435)
    at org.apache.tools.ant.Target.performTasks(Target.java:456)
    at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1393)
    at org.apache.tools.ant.Project.executeTarget(Project.java:1364)
    at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
    at org.apache.tools.ant.Project.executeTargets(Project.java:1248)
    at org.apache.tools.ant.module.bridge.impl.BridgeImpl.run(BridgeImpl.java:286)
    at org.apache.tools.ant.module.run.TargetExecutor.run(TargetExecutor.java:555)
    at org.netbeans.core.execution.RunClassThread.run(RunClassThread.java:153)
BUILD FAILED (total time: 7 seconds)

Does anyone have an idea what I'm missing? Is there a bug in NetBeans or in the 1.8.0_60 SDK or JRE? Thanks for your time & consideration!

Answer 1

You have to change netbeans_jdkhome in netbeans.conf file.

• Close NetBeans if it is running.
• Find the file C:\Program Files\NetBeans 7.3\etc\netbeans.conf
• Change the value for the parameter "netbeans_jdkhome" to the desired JDK version
  E.g.: netbeans_jdkhome="C:\Program Files\Java\jdk1.7.0_21"
• Save the file and start NetBeans again.

Source + more detailed information: https://joanpaon.wordpress.com/2013/06/11/how-to-change-netbeans-default-java-platform-2/