title: Eclipse 2020-06 freezes constantly due to java.util.concurrent.TimeoutException
body: <p>I have recently switched to eclipse 2020-06 for JEE development and it turned out to be a setback. It keeps freezing whenever an action is required: getting into a class definition, pulsing ctrl and selecting any item (classes, methods, ...). The eclipse log is full of these erros:</p>
  <pre><code>java.util.concurrent.TimeoutException
      at java.util.concurrent.CompletableFuture.timedGet(Unknown Source)
      at java.util.concurrent.CompletableFuture.get(Unknown Source)
      at org.eclipse.lsp4e.LanguageServerWrapper.supportsWorkspaceFolderCapability(LanguageServerWrapper.java:544)
      at org.eclipse.lsp4e.LanguageServerWrapper.canOperate(LanguageServerWrapper.java:863)
      at org.eclipse.lsp4e.LanguageServiceAccessor.lambda$6(LanguageServiceAccessor.java:361)
      at java.util.stream.ReferencePipeline$2$1.accept(Unknown Source)
      at java.util.stream.ReferencePipeline$2$1.accept(Unknown Source)
      at java.util.HashMap$KeySpliterator.forEachRemaining(Unknown Source)
      at java.util.stream.AbstractPipeline.copyInto(Unknown Source)
      at java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source)
      at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(Unknown Source)
      at java.util.stream.AbstractPipeline.evaluate(Unknown Source)
      at java.util.stream.ReferencePipeline.collect(Unknown Source)
      at org.eclipse.lsp4e.LanguageServiceAccessor.getLSWrappers(LanguageServiceAccessor.java:362)
      at org.eclipse.lsp4e.LanguageServiceAccessor.getLanguageServers(LanguageServiceAccessor.java:588)
      at org.eclipse.lsp4e.operations.rename.LSPRenameHandler.isEnabled(LSPRenameHandler.java:128)
      at org.eclipse.ui.internal.handlers.HandlerProxy.isEnabled(HandlerProxy.java:300)
      at org.eclipse.ui.internal.handlers.E4HandlerProxy.canExecute(E4HandlerProxy.java:78)
      at sun.reflect.GeneratedMethodAccessor4.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:58)
      at org.eclipse.e4.core.internal.di.InjectorImpl.invokeUsingClass(InjectorImpl.java:319)
      at org.eclipse.e4.core.internal.di.InjectorImpl.invoke(InjectorImpl.java:253)
      at org.eclipse.e4.core.contexts.ContextInjectionFactory.invoke(ContextInjectionFactory.java:173)
      at org.eclipse.e4.core.commands.internal.HandlerServiceHandler.isEnabled(HandlerServiceHandler.java:62)
      at org.eclipse.core.commands.Command.isEnabled(Command.java:832)
      at org.eclipse.ui.menus.CommandContributionItem.isEnabled(CommandContributionItem.java:917)
      at org.eclipse.ui.menus.CommandContributionItem.updateMenuItem(CommandContributionItem.java:531)
      at org.eclipse.ui.menus.CommandContributionItem.update(CommandContributionItem.java:484)
      at org.eclipse.ui.menus.CommandContributionItem.update(CommandContributionItem.java:477)
      at org.eclipse.ui.menus.CommandContributionItem.lambda$0(CommandContributionItem.java:935)
      at org.eclipse.jface.bindings.BindingManager.fireBindingManagerChanged(BindingManager.java:903)
      at org.eclipse.jface.bindings.BindingManager.setActiveBindings(BindingManager.java:2183)
      at org.eclipse.jface.bindings.BindingManager.recomputeBindings(BindingManager.java:1744)
      at org.eclipse.jface.bindings.BindingManager.contextManagerChanged(BindingManager.java:693)
      at org.eclipse.core.commands.contexts.ContextManager.fireContextManagerChanged(ContextManager.java:164)
      at org.eclipse.core.commands.contexts.ContextManager.setEventCaching(ContextManager.java:323)
      at org.eclipse.core.commands.contexts.ContextManager.deferUpdates(ContextManager.java:85)
      at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.activate(PartServiceImpl.java:781)
      at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.activate(PartServiceImpl.java:683)
      at org.eclipse.e4.ui.internal.workbench.swt.AbstractPartRenderer.activate(AbstractPartRenderer.java:97)
      at org.eclipse.e4.ui.workbench.renderers.swt.ContributedPartRenderer.lambda$0(ContributedPartRenderer.java:63)
      at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:89)
      at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4213)
      at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1037)
      at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1061)
      at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1046)
      at org.eclipse.swt.widgets.Shell.setActiveControl(Shell.java:1469)
      at org.eclipse.swt.widgets.Shell.WM_MOUSEACTIVATE(Shell.java:2315)
      at org.eclipse.swt.widgets.Control.windowProc(Control.java:4784)
      at org.eclipse.swt.widgets.Canvas.windowProc(Canvas.java:340)
      at org.eclipse.swt.widgets.Decorations.windowProc(Decorations.java:1480)
      at org.eclipse.swt.widgets.Shell.windowProc(Shell.java:2142)
      at org.eclipse.swt.widgets.Display.windowProc(Display.java:4931)
      at org.eclipse.swt.internal.win32.OS.DefWindowProc(Native Method)
      at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:91)
      at org.eclipse.swt.widgets.Control.windowProc(Control.java:4841)
      at org.eclipse.swt.widgets.Display.windowProc(Display.java:4931)
      at org.eclipse.swt.internal.win32.OS.DefWindowProc(Native Method)
      at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:91)
      at org.eclipse.swt.widgets.Control.windowProc(Control.java:4841)
      at org.eclipse.swt.widgets.Display.windowProc(Display.java:4931)
      at org.eclipse.swt.internal.win32.OS.DefWindowProc(Native Method)
      at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:91)
      at org.eclipse.swt.widgets.Control.windowProc(Control.java:4841)
      at org.eclipse.swt.widgets.Display.windowProc(Display.java:4931)
      at org.eclipse.swt.internal.win32.OS.DefWindowProc(Native Method)
      at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:91)
      at org.eclipse.swt.widgets.Control.windowProc(Control.java:4841)
      at org.eclipse.swt.widgets.Display.windowProc(Display.java:4931)
      at org.eclipse.swt.internal.win32.OS.DefWindowProc(Native Method)
      at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:91)
      at org.eclipse.swt.widgets.Control.windowProc(Control.java:4841)
      at org.eclipse.swt.widgets.Display.windowProc(Display.java:4931)
      at org.eclipse.swt.internal.win32.OS.DefWindowProc(Native Method)
      at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:91)
      at org.eclipse.swt.widgets.Control.windowProc(Control.java:4841)
      at org.eclipse.swt.widgets.Display.windowProc(Display.java:4931)
      at org.eclipse.swt.internal.win32.OS.DefWindowProc(Native Method)
      at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:91)
      at org.eclipse.swt.widgets.Control.windowProc(Control.java:4841)
      at org.eclipse.swt.widgets.Display.windowProc(Display.java:4931)
      at org.eclipse.swt.internal.win32.OS.DefWindowProc(Native Method)
      at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:91)
      at org.eclipse.swt.widgets.Control.windowProc(Control.java:4841)
      at org.eclipse.swt.widgets.Display.windowProc(Display.java:4931)
      at org.eclipse.swt.internal.win32.OS.DefWindowProc(Native Method)
      at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:91)
      at org.eclipse.swt.widgets.Control.windowProc(Control.java:4841)
      at org.eclipse.swt.widgets.Display.windowProc(Display.java:4931)
      at org.eclipse.swt.internal.win32.OS.DefWindowProc(Native Method)
      at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:91)
      at org.eclipse.swt.widgets.Control.windowProc(Control.java:4841)
      at org.eclipse.swt.widgets.Display.windowProc(Display.java:4931)
      at org.eclipse.swt.internal.win32.OS.DefWindowProc(Native Method)
      at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:91)
      at org.eclipse.swt.widgets.Control.windowProc(Control.java:4841)
      at org.eclipse.swt.widgets.Display.windowProc(Display.java:4931)
      at org.eclipse.swt.internal.win32.OS.DefWindowProc(Native Method)
      at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:91)
      at org.eclipse.swt.widgets.Control.windowProc(Control.java:4841)
      at org.eclipse.swt.widgets.Display.windowProc(Display.java:4931)
      at org.eclipse.swt.internal.win32.OS.DefWindowProc(Native Method)
      at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:91)
      at org.eclipse.swt.widgets.Control.windowProc(Control.java:4841)
      at org.eclipse.swt.widgets.Display.windowProc(Display.java:4931)
      at org.eclipse.swt.internal.win32.OS.DefWindowProc(Native Method)
      at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:91)
      at org.eclipse.swt.widgets.Control.windowProc(Control.java:4841)
      at org.eclipse.swt.widgets.Display.windowProc(Display.java:4931)
      at org.eclipse.swt.internal.win32.OS.DefWindowProc(Native Method)
      at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:91)
      at org.eclipse.swt.widgets.Control.windowProc(Control.java:4841)
      at org.eclipse.swt.widgets.Canvas.windowProc(Canvas.java:340)
      at org.eclipse.swt.widgets.Display.windowProc(Display.java:4931)
      at org.eclipse.swt.internal.win32.OS.DefWindowProc(Native Method)
      at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:91)
      at org.eclipse.swt.widgets.Control.windowProc(Control.java:4841)
      at org.eclipse.swt.widgets.Canvas.windowProc(Canvas.java:340)
      at org.eclipse.swt.widgets.Display.windowProc(Display.java:4931)
      at org.eclipse.swt.internal.win32.OS.DefWindowProc(Native Method)
      at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:91)
      at org.eclipse.swt.widgets.Control.windowProc(Control.java:4841)
      at org.eclipse.swt.widgets.Display.windowProc(Display.java:4931)
      at org.eclipse.swt.internal.win32.OS.CallWindowProc(Native Method)
      at org.eclipse.swt.widgets.Label.callWindowProc(Label.java:123)
      at org.eclipse.swt.widgets.Control.windowProc(Control.java:4841)
      at org.eclipse.swt.widgets.Display.windowProc(Display.java:4931)
      at org.eclipse.swt.internal.win32.OS.PeekMessage(Native Method)
      at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3625)
      at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1158)
      at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:338)
      at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1047)
      at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:155)
      at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:658)
      at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:338)
      at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:557)
      at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:154)
      at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:150)
      at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:203)
      at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:137)
      at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:107)
      at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:401)
      at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:255)
      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:657)
      at org.eclipse.equinox.launcher.Main.basicRun(Main.java:594)
      at org.eclipse.equinox.launcher.Main.run(Main.java:1447)
  </code></pre>
  <p>The pluggins I'm currently using are JBoss Tools, Spring STS, Subeclipse and Dark Theme.
  I've tried to download the whole IDE again and to uncheck most of the options regarding validations, to no avail. Any ideas?</p>
  <p>Thank you very much!!</p>