Issue launching project with VisualVM eclipse plugin

Question

An internal error occurred during: "Launching ModificationToolkit".

java.lang.NullPointerException
    at org.eclipse.jdt.launching.JavaLaunchDelegate.launch(JavaLaunchDelegate.java:101)
    at org.eclipse.visualvm.launcher.java.VisualVMJavaDelegate.launch(VisualVMJavaDelegate.java:44)
    at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:858)
    at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:707)
    at org.eclipse.debug.internal.ui.DebugUIPlugin.buildAndLaunch(DebugUIPlugin.java:1018)
    at org.eclipse.debug.internal.ui.DebugUIPlugin$8.run(DebugUIPlugin.java:1222)
    at org.eclipse.core.internal.jobs.Worker.run(Worker.java:53)

I've seen this on the Internet a bit, but there doesn't seem to be a resolution for it. My project launches fine without using this plugin, and this issue also affects my other projects (if I attempt to launch using VisualVM).

Using this version of VisualVM - http://visualvm.java.net/eclipse-launcher.html

Answer 1

As I first installed it, (as told on the page you gave me,) it did work. So I need some information first:

• What eclipse version do you use?
• What paths did you set?
• What JDK version(s) do you have installed.
• What VisualVM versions do they have.
• If any seperate installed, what JRE versions do you have?

How to get the paths of your VisualVM plugin:

1. Inside eclipse: open the GLOBAL Preferences (Window>Preferences)
2. In your GLOBAL Preferences: "Run/Debug">"Launching">"VisualVM Configuration"
3. There should be to paths. The first one is the path to the VisualVM Executable. The second one is your JDK home. (the jdk-home path should match the VisualVM's jdk-home path)

How to get the version of VisualVM:

1. Navigate to your JDK folder.
2. Inside the 'bin' folder there should be a executable (with a fancy icon) called 'visualvm' with any extension. (I don't know what os you are using and its irrelevant)
3. Start it...
4. On the menubar: Help>About. On the dialog look at the lower left corner. (Mostly it matches your JDK version)