Documentation tab is no longer showing content

java.lang.NullPointerException
	at org.eclipse.help.internal.server.JettyHelpServer.checkBundle(JettyHelpServer.java:117)
	at org.eclipse.help.internal.server.JettyHelpServer.start(JettyHelpServer.java:108)
	at org.eclipse.help.internal.server.WebappManager.start(WebappManager.java:38)
	at org.eclipse.help.internal.base.BaseHelpSystem.ensureWebappRunning(BaseHelpSystem.java:182)
	at org.eclipse.help.internal.base.BaseHelpSystem.resolve(BaseHelpSystem.java:198)
	at org.eclipse.help.ui.internal.DefaultHelpUI.resolve(DefaultHelpUI.java:363)
	at org.eclipse.ui.internal.help.WorkbenchHelpSystem.resolve(WorkbenchHelpSystem.java:888)
	at com.fusesource.rider.editor.propertysheet.DocumentationSection.createControls(DocumentationSection.java:178)
	at org.eclipse.ui.views.properties.tabbed.TabContents$1.run(TabContents.java:109)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
	at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:49)
	at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)
	at org.eclipse.ui.views.properties.tabbed.TabContents.createControls(TabContents.java:112)
	at org.eclipse.ui.views.properties.tabbed.TabbedPropertySheetPage$SelectionChangedListener.selectionChanged(TabbedPropertySheetPage.java:206)
	at org.eclipse.jface.viewers.Viewer$2.run(Viewer.java:162)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
	at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:49)
	at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)
	at org.eclipse.jface.viewers.Viewer.fireSelectionChanged(Viewer.java:160)
	at org.eclipse.jface.viewers.StructuredViewer.updateSelection(StructuredViewer.java:2162)
	at org.eclipse.jface.viewers.StructuredViewer.handleSelect(StructuredViewer.java:1190)
	at org.eclipse.jface.viewers.StructuredViewer$4.widgetSelected(StructuredViewer.java:1220)
	at org.eclipse.jface.util.OpenStrategy.fireSelectionEvent(OpenStrategy.java:228)
	at org.eclipse.jface.util.OpenStrategy.access$4(OpenStrategy.java:222)
	at org.eclipse.jface.util.OpenStrategy$1.handleEvent(OpenStrategy.java:389)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
	at org.eclipse.swt.widgets.Display.sendEvent(Display.java:3776)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1367)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1390)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1375)
	at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:1187)
	at org.eclipse.ui.internal.views.properties.tabbed.view.TabbedPropertyList.select(TabbedPropertyList.java:664)
	at org.eclipse.ui.internal.views.properties.tabbed.view.TabbedPropertyList$2.mouseUp(TabbedPropertyList.java:156)
	at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:213)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
	at org.eclipse.swt.widgets.Display.sendEvent(Display.java:3776)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1367)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1390)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1375)
	at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:1187)
	at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3622)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3277)
	at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2640)
	at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2604)
	at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2438)
	at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:671)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:664)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:115)
	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:369)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:620)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:575)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1408)
	at org.eclipse.equinox.launcher.Main.main(Main.java:1384)