java.lang.ClassNotFoundException: org.eclipse.core.internal.net.Activator
   at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:513)
   at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:429)
   at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:417)
   at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.loadClass(DefaultClassLoader.java:107)
   at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
   at org.eclipse.osgi.internal.loader.BundleLoader.loadClass(BundleLoader.java:345)
   at org.eclipse.osgi.framework.internal.core.BundleHost.loadClass(BundleHost.java:229)
Caused: org.osgi.framework.BundleException: The activator org.eclipse.core.internal.net.Activator for bundle org.eclipse.core.net is invalid
   at org.eclipse.osgi.framework.internal.core.AbstractBundle.loadBundleActivator(AbstractBundle.java:171)
   at org.eclipse.osgi.framework.internal.core.BundleContextImpl.start(BundleContextImpl.java:679)
   at org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.java:381)
   at org.eclipse.osgi.framework.internal.core.AbstractBundle.resume(AbstractBundle.java:389)
   at org.eclipse.osgi.framework.internal.core.Framework.resumeBundle(Framework.java:1131)
   at org.eclipse.osgi.framework.internal.core.StartLevelManager.resumeBundles(StartLevelManager.java:559)
   at org.eclipse.osgi.framework.internal.core.StartLevelManager.resumeBundles(StartLevelManager.java:544)
   at org.eclipse.osgi.framework.internal.core.StartLevelManager.incFWSL(StartLevelManager.java:457)
   at org.eclipse.osgi.framework.internal.core.StartLevelManager.doSetStartLevel(StartLevelManager.java:243)
   at org.eclipse.osgi.framework.internal.core.EquinoxLauncher.internalStart(EquinoxLauncher.java:271)
   at org.eclipse.osgi.framework.internal.core.EquinoxLauncher.start(EquinoxLauncher.java:241)
   at org.eclipse.osgi.launch.Equinox.start(Equinox.java:258)
   at org.netbeans.core.netigso.Netigso.start(Netigso.java:173)
   at org.netbeans.NetigsoFramework.startFramework(NetigsoFramework.java:291)
   at org.netbeans.ModuleManager.enable(ModuleManager.java:1164)
   at org.netbeans.ModuleManager.enable(ModuleManager.java:986)
   at org.netbeans.core.startup.ModuleList.installNew(ModuleList.java:340)
   at org.netbeans.core.startup.ModuleList.trigger(ModuleList.java:276)
   at org.netbeans.core.startup.ModuleSystem.restore(ModuleSystem.java:295)
   at org.netbeans.core.startup.Main.getModuleSystem(Main.java:169)
   at org.netbeans.core.startup.Main.start(Main.java:305)
   at org.netbeans.core.startup.TopThreadGroup.run(TopThreadGroup.java:123)
   at java.lang.Thread.run(Thread.java:680)