java.lang.AssertionError: Nulls in [null] from org.netbeans.modules.xslt.project.XsltProjectOperations@53266b
        at org.netbeans.spi.project.support.ProjectOperations.getDataFiles(ProjectOperations.java:96)
        at org.netbeans.modules.project.uiapi.ProjectCopyPanel.hasExternalSources(ProjectCopyPanel.java:343)
        at org.netbeans.modules.project.uiapi.ProjectCopyPanel.setProject(ProjectCopyPanel.java:335)
        at org.netbeans.modules.project.uiapi.ProjectCopyPanel.<init>(ProjectCopyPanel.java:82)
        at org.netbeans.modules.project.uiapi.DefaultProjectOperationsImplementation.moveProject(DefaultProjectOperationsImplementation.java:311)
        at org.netbeans.spi.project.ui.support.DefaultProjectOperations.performDefaultMoveOperation(DefaultProjectOperations.java:131)
        at org.netbeans.modules.xslt.project.XsltproActionProvider.invokeAction(XsltproActionProvider.java:102)
        at org.netbeans.modules.project.ui.actions.ProjectAction.actionPerformed(ProjectAction.java:129)
        at org.netbeans.modules.project.ui.actions.LookupSensitiveAction.actionPerformed(LookupSensitiveAction.java:161)
        at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
        at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
        at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
        at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
        at javax.swing.AbstractButton.doClick(AbstractButton.java:357)
        at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:1225)
        at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:1266)
        at java.awt.Component.processMouseEvent(Component.java:6134)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3265)
        at java.awt.Component.processEvent(Component.java:5899)
        at java.awt.Container.processEvent(Container.java:2023)
        at java.awt.Component.dispatchEventImpl(Component.java:4501)
        at java.awt.Container.dispatchEventImpl(Container.java:2081)
        at java.awt.Component.dispatchEvent(Component.java:4331)
        at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4301)
        at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:3965)
        at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:3895)
        at java.awt.Container.dispatchEventImpl(Container.java:2067)
        at java.awt.Window.dispatchEventImpl(Window.java:2458)
        at java.awt.Component.dispatchEvent(Component.java:4331)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
        at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:104)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)