java.lang.IllegalStateException: Trying to set lookup org.openide.util.Lookup$Empty@3f77b3cd but there already is java.lang.ref.WeakReference@5626e185 for component: org.netbeans.core.HtmlBrowserComponent[Web Browser,0,0,735x439,invalid,layout=java.awt.BorderLayout,alignmentX=0.0,alignmentY=0.0,border=,flags=256,maximumSize=,minimumSize=,preferredSize=]
   at org.openide.windows.TopComponent.setLookup(TopComponent.java:1376)
   at org.openide.windows.TopComponent.associateLookup(TopComponent.java:1361)
   at org.netbeans.core.HtmlBrowserComponent.componentActivated(HtmlBrowserComponent.java:192)
   at org.openide.windows.WindowManager.activateComponent(WindowManager.java:291)
   at org.netbeans.core.windows.WindowManagerImpl.notifyRegistryTopComponentActivated(WindowManagerImpl.java:1128)
   at org.netbeans.core.windows.Central.setModeSelectedTopComponent(Central.java:750)
   at org.netbeans.core.windows.Central.userActivatedTopComponent(Central.java:1917)
   at org.netbeans.core.windows.view.DefaultView.userSelectedTab(DefaultView.java:680)
   at org.netbeans.core.windows.view.ui.TabbedHandler.stateChanged(TabbedHandler.java:302)
   at org.openide.util.ChangeSupport.fireChange(ChangeSupport.java:133)
   at org.openide.util.ChangeSupport.fireChange(ChangeSupport.java:119)
   at org.netbeans.core.windows.view.ui.tabcontrol.AbstractTabbedImpl.fireStateChanged(AbstractTabbedImpl.java:500)
   at org.netbeans.core.windows.view.ui.tabcontrol.TabbedAdapter$1.stateChanged(TabbedAdapter.java:81)
   at org.openide.util.ChangeSupport.fireChange(ChangeSupport.java:133)
   at org.openide.util.ChangeSupport.fireChange(ChangeSupport.java:119)
   at org.netbeans.swing.tabcontrol.plaf.DefaultTabSelectionModel.setSelectedIndex(DefaultTabSelectionModel.java:111)
   at org.netbeans.swing.tabcontrol.plaf.BasicTabDisplayerUI$BasicDisplayerMouseListener.performCommand(BasicTabDisplayerUI.java:770)
   at org.netbeans.swing.tabcontrol.plaf.BasicTabDisplayerUI$BasicDisplayerMouseListener.potentialCommand(BasicTabDisplayerUI.java:759)
   at org.netbeans.swing.tabcontrol.plaf.BasicTabDisplayerUI$BasicDisplayerMouseListener.mousePressed(BasicTabDisplayerUI.java:734)
   at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:262)
   at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:262)
   at java.awt.Component.processMouseEvent(Component.java:6370)
   at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
   at java.awt.Component.processEvent(Component.java:6138)
   at java.awt.Container.processEvent(Container.java:2085)
   at java.awt.Component.dispatchEventImpl(Component.java:4735)
   at java.awt.Container.dispatchEventImpl(Container.java:2143)
   at java.awt.Component.dispatchEvent(Component.java:4565)
   at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4621)
   at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:4279)
   at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:4212)
   at java.awt.Container.dispatchEventImpl(Container.java:2129)
   at java.awt.Window.dispatchEventImpl(Window.java:2478)
   at java.awt.Component.dispatchEvent(Component.java:4565)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:679)
   at java.awt.EventQueue.access$000(EventQueue.java:85)
   at java.awt.EventQueue$1.run(EventQueue.java:638)
   at java.awt.EventQueue$1.run(EventQueue.java:636)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
   at java.awt.EventQueue$2.run(EventQueue.java:652)
   at java.awt.EventQueue$2.run(EventQueue.java:650)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:649)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:162)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)