java.lang.NullPointerException
        at org.openide.filesystems.MIMESupport.findMIMEType(MIMESupport.java:93)
        at org.openide.filesystems.FileUtil.getMIMEType(FileUtil.java:989)
        at org.netbeans.modules.latex.refactoring.actions.ActionsImplementationProviderImpl.canFindUsages(ActionsImplementationProviderImpl.java:91)
        at org.netbeans.modules.refactoring.api.impl.ActionsImplementationFactory.canFindUsages(ActionsImplementationFactory.java:77)
        at org.netbeans.modules.refactoring.spi.impl.WhereUsedAction.enable(WhereUsedAction.java:74)
        at org.netbeans.modules.refactoring.spi.impl.RefactoringGlobalAction.enable(RefactoringGlobalAction.java:135)
        at org.openide.util.actions.NodeAction.isEnabled(NodeAction.java:202)
        at org.openide.awt.Actions$MenuBridge.updateState(Actions.java:894)
        at org.openide.awt.Actions$MenuItem.synchMenuPresenters(Actions.java:1235)
        at org.openide.awt.DynaMenuModel.checkSubmenu(DynaMenuModel.java:182)
        at org.openide.awt.MenuBar$LazyMenu.stateChanged(MenuBar.java:537)
        at javax.swing.DefaultButtonModel.fireStateChanged(DefaultButtonModel.java:362)
        at javax.swing.DefaultButtonModel.setSelected(DefaultButtonModel.java:228)
        at javax.swing.JMenu.setSelected(JMenu.java:280)
        at javax.swing.JMenu.menuSelectionChanged(JMenu.java:1251)
        at javax.swing.MenuSelectionManager.setSelectedPath(MenuSelectionManager.java:89)
        at javax.swing.plaf.basic.BasicMenuUI$Handler.mouseEntered(BasicMenuUI.java:517)
        at java.awt.Component.processMouseEvent(Component.java:5526)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3135)
        at java.awt.Component.processEvent(Component.java:5282)
        at java.awt.Container.processEvent(Container.java:1966)
        at java.awt.Component.dispatchEventImpl(Component.java:3984)
        at java.awt.Container.dispatchEventImpl(Container.java:2024)
        at java.awt.Component.dispatchEvent(Component.java:3819)
        at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4212)
        at java.awt.LightweightDispatcher.trackMouseEnterExit(LightweightDispatcher.java:4017)
        at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:3874)
        at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:3822)
        at java.awt.Container.dispatchEventImpl(Container.java:2010)
        at java.awt.Window.dispatchEventImpl(Window.java:1791)
        at java.awt.Component.dispatchEvent(Component.java:3819)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
        at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:242)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:163)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)