I have done a lot of clean installs but not no avail. The native hooks or polling is unticked by default. When I turn it on though, I finally got an error message when opening the play template editor rather than just a blank sheet, see below.
What I also noticed, is that if I want to go to Play plugin settings (Window -> Preferences -> Play) it throws an error too and doesn't continue. The second stack trace belongs to this one.
org.eclipse.core.runtime.CoreException: Plug-in org.scala-ide.play2 was unable to load class org.scalaide.play2.templateeditor.sse.TemplateStructuredEditor.
at org.eclipse.core.internal.registry.osgi.RegistryStrategyOSGI.throwException(RegistryStrategyOSGI.java:194)
at org.eclipse.core.internal.registry.osgi.RegistryStrategyOSGI.createExecutableExtension(RegistryStrategyOSGI.java:176)
at org.eclipse.core.internal.registry.ExtensionRegistry.createExecutableExtension(ExtensionRegistry.java:905)
at org.eclipse.core.internal.registry.ConfigurationElement.createExecutableExtension(ConfigurationElement.java:243)
at org.eclipse.core.internal.registry.ConfigurationElementHandle.createExecutableExtension(ConfigurationElementHandle.java:55)
at org.eclipse.ui.internal.WorkbenchPlugin$1.run(WorkbenchPlugin.java:294)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.ui.internal.WorkbenchPlugin.createExtension(WorkbenchPlugin.java:289)
at org.eclipse.ui.internal.registry.EditorDescriptor.createEditor(EditorDescriptor.java:235)
at org.eclipse.ui.internal.EditorReference.createPart(EditorReference.java:349)
at org.eclipse.ui.internal.e4.compatibility.CompatibilityPart.createPart(CompatibilityPart.java:265)
at org.eclipse.ui.internal.e4.compatibility.CompatibilityEditor.createPart(CompatibilityEditor.java:63)
at org.eclipse.ui.internal.e4.compatibility.CompatibilityPart.create(CompatibilityPart.java:303)
at org.eclipse.e4.core.internal.di.InjectorImpl.processAnnotated(InjectorImpl.java:888)
at org.eclipse.e4.core.internal.di.InjectorImpl.processAnnotated(InjectorImpl.java:869)
at org.eclipse.e4.core.internal.di.InjectorImpl.inject(InjectorImpl.java:120)
at org.eclipse.e4.core.internal.di.InjectorImpl.internalMake(InjectorImpl.java:337)
at org.eclipse.e4.core.internal.di.InjectorImpl.make(InjectorImpl.java:258)
at org.eclipse.e4.core.contexts.ContextInjectionFactory.make(ContextInjectionFactory.java:162)
at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.createFromBundle(ReflectionContributionFactory.java:104)
at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.doCreate(ReflectionContributionFactory.java:73)
at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.create(ReflectionContributionFactory.java:55)
at org.eclipse.e4.ui.workbench.renderers.swt.ContributedPartRenderer.createWidget(ContributedPartRenderer.java:127)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createWidget(PartRenderingEngine.java:983)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:662)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:766)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.access$2(PartRenderingEngine.java:737)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$7.run(PartRenderingEngine.java:731)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createGui(PartRenderingEngine.java:715)
at org.eclipse.e4.ui.internal.workbench.PartServiceImpl$1.handleEvent(PartServiceImpl.java:94)
at org.eclipse.e4.ui.services.internal.events.UIEventHandler$1.run(UIEventHandler.java:40)
at org.eclipse.swt.widgets.Synchronizer.syncExec(Synchronizer.java:187)
at org.eclipse.ui.internal.UISynchronizer.syncExec(UISynchronizer.java:156)
at org.eclipse.swt.widgets.Display.syncExec(Display.java:4734)
at org.eclipse.e4.ui.internal.workbench.swt.E4Application$1.syncExec(E4Application.java:218)
at org.eclipse.e4.ui.services.internal.events.UIEventHandler.handleEvent(UIEventHandler.java:36)
at org.eclipse.equinox.internal.event.EventHandlerWrapper.handleEvent(EventHandlerWrapper.java:197)
at org.eclipse.equinox.internal.event.EventHandlerTracker.dispatchEvent(EventHandlerTracker.java:197)
at org.eclipse.equinox.internal.event.EventHandlerTracker.dispatchEvent(EventHandlerTracker.java:1)
at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:230)
at org.eclipse.osgi.framework.eventmgr.ListenerQueue.dispatchEventSynchronous(ListenerQueue.java:148)
at org.eclipse.equinox.internal.event.EventAdminImpl.dispatchEvent(EventAdminImpl.java:135)
at org.eclipse.equinox.internal.event.EventAdminImpl.sendEvent(EventAdminImpl.java:78)
at org.eclipse.equinox.internal.event.EventComponent.sendEvent(EventComponent.java:39)
at org.eclipse.e4.ui.services.internal.events.EventBroker.send(EventBroker.java:81)
at org.eclipse.e4.ui.internal.workbench.UIEventPublisher.notifyChanged(UIEventPublisher.java:59)
at org.eclipse.emf.common.notify.impl.BasicNotifierImpl.eNotify(BasicNotifierImpl.java:374)
at org.eclipse.e4.ui.model.application.ui.impl.ElementContainerImpl.setSelectedElement(ElementContainerImpl.java:171)
at org.eclipse.e4.ui.internal.workbench.ModelServiceImpl.showElementInWindow(ModelServiceImpl.java:488)
at org.eclipse.e4.ui.internal.workbench.ModelServiceImpl.bringToTop(ModelServiceImpl.java:454)
at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.delegateBringToTop(PartServiceImpl.java:694)
at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.bringToTop(PartServiceImpl.java:387)
at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.showPart(PartServiceImpl.java:1134)
at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditor(WorkbenchPage.java:3210)
at org.eclipse.ui.internal.WorkbenchPage.access$23(WorkbenchPage.java:3125)
at org.eclipse.ui.internal.WorkbenchPage$9.run(WorkbenchPage.java:3107)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:3102)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:3066)
at org.eclipse.ui.actions.OpenWithMenu.openEditor(OpenWithMenu.java:338)
at org.eclipse.ui.actions.OpenWithMenu$2.handleEvent(OpenWithMenu.java:180)
Caused by: java.lang.ClassNotFoundException: An error occurred while automatically activating bundle org.scala-ide.play2 (848).
at org.eclipse.osgi.internal.hooks.EclipseLazyStarter.postFindLocalClass(EclipseLazyStarter.java:116)
at org.eclipse.osgi.internal.loader.classpath.ClasspathManager.findLocalClass(ClasspathManager.java:531)
at org.eclipse.osgi.internal.loader.ModuleClassLoader.findLocalClass(ModuleClassLoader.java:324)
at org.eclipse.osgi.internal.loader.BundleLoader.findLocalClass(BundleLoader.java:320)
at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:395)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:345)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:337)
at org.eclipse.osgi.internal.loader.ModuleClassLoader.loadClass(ModuleClassLoader.java:160)
at java.lang.ClassLoader.loadClass(Unknown Source)
at org.eclipse.osgi.internal.framework.EquinoxBundle.loadClass(EquinoxBundle.java:568)
at org.eclipse.core.internal.registry.osgi.RegistryStrategyOSGI.createExecutableExtension(RegistryStrategyOSGI.java:174)
at org.eclipse.core.internal.registry.ExtensionRegistry.createExecutableExtension(ExtensionRegistry.java:905)
at org.eclipse.core.internal.registry.ConfigurationElement.createExecutableExtension(ConfigurationElement.java:243)
at org.eclipse.core.internal.registry.ConfigurationElementHandle.createExecutableExtension(ConfigurationElementHandle.java:55)
at org.eclipse.ui.internal.WorkbenchPlugin$1.run(WorkbenchPlugin.java:294)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.ui.internal.WorkbenchPlugin.createExtension(WorkbenchPlugin.java:289)
at org.eclipse.ui.internal.dialogs.WorkbenchPreferenceNode.createPage(WorkbenchPreferenceNode.java:48)
at org.eclipse.jface.preference.PreferenceDialog.createPage(PreferenceDialog.java:1372)
at org.eclipse.ui.internal.dialogs.FilteredPreferenceDialog.createPage(FilteredPreferenceDialog.java:385)
at org.eclipse.jface.preference.PreferenceDialog.showPage(PreferenceDialog.java:1259)
at org.eclipse.ui.internal.dialogs.FilteredPreferenceDialog.showPage(FilteredPreferenceDialog.java:699)
at org.eclipse.jface.preference.PreferenceDialog$9$1.run(PreferenceDialog.java:730)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.jface.preference.PreferenceDialog$9.selectionChanged(PreferenceDialog.java:725)
at org.eclipse.jface.viewers.StructuredViewer$3.run(StructuredViewer.java:876)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:50)
at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:178)
at org.eclipse.jface.viewers.StructuredViewer.firePostSelectionChanged(StructuredViewer.java:873)
at org.eclipse.jface.viewers.StructuredViewer.handlePostSelect(StructuredViewer.java:1217)
at org.eclipse.jface.viewers.StructuredViewer$5.widgetSelected(StructuredViewer.java:1243)
at org.eclipse.jface.util.OpenStrategy.firePostSelectionEvent(OpenStrategy.java:265)
at org.eclipse.jface.util.OpenStrategy.access$5(OpenStrategy.java:259)
at org.eclipse.jface.util.OpenStrategy$1$2.run(OpenStrategy.java:440)
at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:136)
at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4147)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3764)
at org.eclipse.jface.window.Window.runEventLoop(Window.java:832)
at org.eclipse.jface.window.Window.open(Window.java:808)
at org.eclipse.ui.internal.dialogs.WorkbenchPreferenceDialog.open(WorkbenchPreferenceDialog.java:221)
at org.eclipse.ui.internal.OpenPreferencesAction.run(OpenPreferencesAction.java:66)
at org.eclipse.jface.action.Action.runWithEvent(Action.java:519)
at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:595)
at org.eclipse.jface.action.ActionContributionItem.access$2(ActionContributionItem.java:511)
at org.eclipse.jface.action.ActionContributionItem$5.handleEvent(ActionContributionItem.java:420)
... 26 more
Caused by: org.osgi.framework.BundleException: Exception in org.scalaide.play2.PlayPlugin.start() of bundle org.scala-ide.play2.
at org.eclipse.osgi.internal.framework.BundleContextImpl.startActivator(BundleContextImpl.java:792)
at org.eclipse.osgi.internal.framework.BundleContextImpl.start(BundleContextImpl.java:721)
at org.eclipse.osgi.internal.framework.EquinoxBundle.startWorker0(EquinoxBundle.java:936)
at org.eclipse.osgi.internal.framework.EquinoxBundle$EquinoxModule.startWorker(EquinoxBundle.java:319)
at org.eclipse.osgi.container.Module.doStart(Module.java:571)
at org.eclipse.osgi.container.Module.start(Module.java:439)
at org.eclipse.osgi.framework.util.SecureAction.start(SecureAction.java:454)
at org.eclipse.osgi.internal.hooks.EclipseLazyStarter.postFindLocalClass(EclipseLazyStarter.java:107)
... 72 more
Caused by: java.lang.NoClassDefFoundError: org/scalaide/core/IScalaPlugin$
at org.scalaide.play2.PlayPlugin.asPlayProject(PlayPlugin.scala:51)
at org.scalaide.play2.PlayPlugin$$anonfun$initializeProjects$2.apply(PlayPlugin.scala:59)
at org.scalaide.play2.PlayPlugin$$anonfun$initializeProjects$2.apply(PlayPlugin.scala:57)
at scala.collection.TraversableLike$WithFilter$$anonfun$foreach$1.apply(TraversableLike.scala:778)
at scala.collection.IndexedSeqOptimized$class.foreach(IndexedSeqOptimized.scala:33)
at scala.collection.mutable.ArrayOps$ofRef.foreach(ArrayOps.scala:186)
at scala.collection.TraversableLike$WithFilter.foreach(TraversableLike.scala:777)
at org.scalaide.play2.PlayPlugin.initializeProjects(PlayPlugin.scala:57)
at org.scalaide.play2.PlayPlugin.start(PlayPlugin.scala:42)
at org.eclipse.osgi.internal.framework.BundleContextImpl$3.run(BundleContextImpl.java:771)
at org.eclipse.osgi.internal.framework.BundleContextImpl$3.run(BundleContextImpl.java:1)
at java.security.AccessController.doPrivileged(Native Method)
at org.eclipse.osgi.internal.framework.BundleContextImpl.startActivator(BundleContextImpl.java:764)
... 79 more
Caused by: java.lang.ClassNotFoundException: org.scalaide.core.IScalaPlugin$ cannot be found by org.scala-ide.play2_0.4.5.v-2_11-201410211329-719d42a
at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:432)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:345)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:337)
at org.eclipse.osgi.internal.loader.ModuleClassLoader.loadClass(ModuleClassLoader.java:160)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 92 more
eclipse.buildId=4.4.1.M20140925-0400
java.version=1.8.0_25
java.vendor=Oracle Corporation
BootLoader constants: OS=win32, ARCH=x86_64, WS=win32, NL=nl_NL
Framework arguments: -product org.eclipse.epp.package.jee.product
Command-line arguments: -os win32 -ws win32 -arch x86_64 -product org.eclipse.epp.package.jee.product
org.eclipse.equinox.registry
Error
Tue Oct 28 13:24:08 CET 2014
Unable to create the selected preference page.
java.lang.ClassNotFoundException: An error occurred while automatically activating bundle org.scala-ide.play2 (848).
at org.eclipse.osgi.internal.hooks.EclipseLazyStarter.postFindLocalClass(EclipseLazyStarter.java:116)
at org.eclipse.osgi.internal.loader.classpath.ClasspathManager.findLocalClass(ClasspathManager.java:531)
at org.eclipse.osgi.internal.loader.ModuleClassLoader.findLocalClass(ModuleClassLoader.java:324)
at org.eclipse.osgi.internal.loader.BundleLoader.findLocalClass(BundleLoader.java:320)
at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:395)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:345)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:337)
at org.eclipse.osgi.internal.loader.ModuleClassLoader.loadClass(ModuleClassLoader.java:160)
at java.lang.ClassLoader.loadClass(Unknown Source)
at org.eclipse.osgi.internal.framework.EquinoxBundle.loadClass(EquinoxBundle.java:568)
at org.eclipse.core.internal.registry.osgi.RegistryStrategyOSGI.createExecutableExtension(RegistryStrategyOSGI.java:174)
at org.eclipse.core.internal.registry.ExtensionRegistry.createExecutableExtension(ExtensionRegistry.java:905)
at org.eclipse.core.internal.registry.ConfigurationElement.createExecutableExtension(ConfigurationElement.java:243)
at org.eclipse.core.internal.registry.ConfigurationElementHandle.createExecutableExtension(ConfigurationElementHandle.java:55)
at org.eclipse.ui.internal.WorkbenchPlugin$1.run(WorkbenchPlugin.java:294)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.ui.internal.WorkbenchPlugin.createExtension(WorkbenchPlugin.java:289)
at org.eclipse.ui.internal.dialogs.WorkbenchPreferenceNode.createPage(WorkbenchPreferenceNode.java:48)
at org.eclipse.jface.preference.PreferenceDialog.createPage(PreferenceDialog.java:1372)
at org.eclipse.ui.internal.dialogs.FilteredPreferenceDialog.createPage(FilteredPreferenceDialog.java:385)
at org.eclipse.jface.preference.PreferenceDialog.showPage(PreferenceDialog.java:1259)
at org.eclipse.ui.internal.dialogs.FilteredPreferenceDialog.showPage(FilteredPreferenceDialog.java:699)
at org.eclipse.jface.preference.PreferenceDialog$9$1.run(PreferenceDialog.java:730)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.jface.preference.PreferenceDialog$9.selectionChanged(PreferenceDialog.java:725)
at org.eclipse.jface.viewers.StructuredViewer$3.run(StructuredViewer.java:876)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:50)
at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:178)
at org.eclipse.jface.viewers.StructuredViewer.firePostSelectionChanged(StructuredViewer.java:873)
at org.eclipse.jface.viewers.StructuredViewer.handlePostSelect(StructuredViewer.java:1217)
at org.eclipse.jface.viewers.StructuredViewer$5.widgetSelected(StructuredViewer.java:1243)
at org.eclipse.jface.util.OpenStrategy.firePostSelectionEvent(OpenStrategy.java:265)
at org.eclipse.jface.util.OpenStrategy.access$5(OpenStrategy.java:259)
at org.eclipse.jface.util.OpenStrategy$1$2.run(OpenStrategy.java:440)
at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:136)
at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4147)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3764)
at org.eclipse.jface.window.Window.runEventLoop(Window.java:832)
at org.eclipse.jface.window.Window.open(Window.java:808)
at org.eclipse.ui.internal.dialogs.WorkbenchPreferenceDialog.open(WorkbenchPreferenceDialog.java:221)
at org.eclipse.ui.internal.OpenPreferencesAction.run(OpenPreferencesAction.java:66)
at org.eclipse.jface.action.Action.runWithEvent(Action.java:519)
at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:595)
at org.eclipse.jface.action.ActionContributionItem.access$2(ActionContributionItem.java:511)
at org.eclipse.jface.action.ActionContributionItem$5.handleEvent(ActionContributionItem.java:420)