Scala Editor in Eclipse not working

Question

I installed the latest Scala IDE for Eclipse

http://scala-ide.org/download/current.html

Now I'm trying to open the .scala.html file using the Scala editor, and it says Failed to create the part controls with the errors below. Troubleshooting indicates enabling JDT weaving, which is already enabled.

Another site that links to this error: https://github.com/scala-ide/scala-ide-play2/issues/33

I also tried to add Scala nature to the project, it does nothing.

How to edit .scala.html files in Eclipse? This is an important task when developing the Play application, so I'm looking for an alternative if there is no fix.

 java.lang.ClassCastException: org.eclipse.jdt.internal.core.CompilationUnit cannot be cast to scala.tools.eclipse.InteractiveCompilationUnit at scala.tools.eclipse.ScalaCompilationUnitEditor$class.getInteractiveCompilationUnit(ScalaCompilationUnitEditor.scala:84) at scala.tools.eclipse.ScalaSourceFileEditor.getInteractiveCompilationUnit(ScalaSourceFileEditor.scala:68) at scala.tools.eclipse.ScalaSourceFileEditor.createPartControl(ScalaSourceFileEditor.scala:297) at org.eclipse.ui.internal.e4.compatibility.CompatibilityPart.createPartControl(CompatibilityPart.java:129) at org.eclipse.ui.internal.e4.compatibility.CompatibilityEditor.createPartControl(CompatibilityEditor.java:95) at org.eclipse.ui.internal.e4.compatibility.CompatibilityPart.create(CompatibilityPart.java:300) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:56) at org.eclipse.e4.core.internal.di.InjectorImpl.processAnnotated(InjectorImpl.java:859) at org.eclipse.e4.core.internal.di.InjectorImpl.processAnnotated(InjectorImpl.java:839) at org.eclipse.e4.core.internal.di.InjectorImpl.inject(InjectorImpl.java:111) at org.eclipse.e4.core.internal.di.InjectorImpl.internalMake(InjectorImpl.java:319) at org.eclipse.e4.core.internal.di.InjectorImpl.make(InjectorImpl.java:240) at org.eclipse.e4.core.contexts.ContextInjectionFactory.make(ContextInjectionFactory.java:161) at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.createFromBundle(ReflectionContributionFactory.java:102) at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.doCreate(ReflectionContributionFactory.java:71) at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.create(ReflectionContributionFactory.java:53) at org.eclipse.e4.ui.workbench.renderers.swt.ContributedPartRenderer.createWidget(ContributedPartRenderer.java:141) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createWidget(PartRenderingEngine.java:896) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:630) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:732) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.access$2(PartRenderingEngine.java:703) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$7.run(PartRenderingEngine.java:697) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createGui(PartRenderingEngine.java:682) at org.eclipse.e4.ui.workbench.renderers.swt.StackRenderer.showTab(StackRenderer.java:1114) at org.eclipse.e4.ui.workbench.renderers.swt.LazyStackRenderer$1.handleEvent(LazyStackRenderer.java:67) at org.eclipse.e4.ui.services.internal.events.UIEventHandler$1.run(UIEventHandler.java:41) at org.eclipse.swt.widgets.Synchronizer.syncExec(Synchronizer.java:180) at org.eclipse.ui.internal.UISynchronizer.syncExec(UISynchronizer.java:150) at org.eclipse.swt.widgets.Display.syncExec(Display.java:4687) at org.eclipse.e4.ui.internal.workbench.swt.E4Application$1.syncExec(E4Application.java:187) at org.eclipse.e4.ui.services.internal.events.UIEventHandler.handleEvent(UIEventHandler.java:38) 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:58) 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:418) at org.eclipse.e4.ui.internal.workbench.ModelServiceImpl.bringToTop(ModelServiceImpl.java:385) at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.delegateBringToTop(PartServiceImpl.java:579) at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.bringToTop(PartServiceImpl.java:315) at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.showPart(PartServiceImpl.java:985) at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditor(WorkbenchPage.java:3079) at org.eclipse.ui.internal.WorkbenchPage.access$22(WorkbenchPage.java:3003) at org.eclipse.ui.internal.WorkbenchPage$8.run(WorkbenchPage.java:2985) at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70) at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2981) at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2940) at org.eclipse.ui.actions.OpenWithMenu.openEditor(OpenWithMenu.java:338) at org.eclipse.ui.actions.OpenWithMenu$2.handleEvent(OpenWithMenu.java:180) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053) at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4169) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3758) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1029) at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:923) at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:86) at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:588) at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332) at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:543) at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149) at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:124) at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196) at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110) at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:353) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:180) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:629) at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584) at org.eclipse.equinox.launcher.Main.run(Main.java:1438) at org.eclipse.equinox.launcher.Main.main(Main.java:1414) 

Answer 1

Are both the Scala IDE and Play plugin installed? On the Scala IDE update site, the Play plugin will appear under the Incubation category.

If you don’t need to reuse an existing Eclipse installation, the easiest way to get started is to use the pre-packaged Scala IDE package, which is an Eclipse installation with all the necessary plugins preinstalled, including Play. You can download the right one for your platform here .