Idea complained...

[klahnakoski]

This appeared after closing another project window.

null
java.lang.NullPointerException
	at com.wix.rt.build.RTFileListener.stop(RTFileListener.java:73)
	at com.wix.rt.RTProjectComponent.disposeComponent(RTProjectComponent.java:75)
	at com.intellij.openapi.components.impl.ComponentManagerImpl.disposeComponents(ComponentManagerImpl.java:149)
	at com.intellij.openapi.project.impl.ProjectImpl.dispose(ProjectImpl.java:369)
	at com.intellij.openapi.util.Disposer$1.execute(Disposer.java:48)
	at com.intellij.openapi.util.Disposer$1.execute(Disposer.java:44)
	at com.intellij.openapi.util.objectTree.ObjectNode$1.execute(ObjectNode.java:138)
	at com.intellij.openapi.util.objectTree.ObjectNode$1.execute(ObjectNode.java:107)
	at com.intellij.openapi.util.objectTree.ObjectTree.executeActionWithRecursiveGuard(ObjectTree.java:151)
	at com.intellij.openapi.util.objectTree.ObjectNode.execute(ObjectNode.java:107)
	at com.intellij.openapi.util.objectTree.ObjectTree.executeAll(ObjectTree.java:137)
	at com.intellij.openapi.util.Disposer.dispose(Disposer.java:125)
	at com.intellij.openapi.util.Disposer.dispose(Disposer.java:121)
	at com.intellij.openapi.project.impl.ProjectManagerImpl.a(ProjectManagerImpl.java:680)
	at com.intellij.openapi.application.impl.ApplicationImpl.runWriteAction(ApplicationImpl.java:1031)
	at com.intellij.openapi.project.impl.ProjectManagerImpl.a(ProjectManagerImpl.java:674)
	at com.intellij.openapi.project.impl.ProjectManagerImpl.closeAndDispose(ProjectManagerImpl.java:698)
	at com.intellij.ide.impl.ProjectUtil.closeAndDispose(ProjectUtil.java:91)
	at com.intellij.openapi.wm.impl.IdeFrameImpl$1.windowClosing(IdeFrameImpl.java:193)
	at java.awt.AWTEventMulticaster.windowClosing(AWTEventMulticaster.java:349)
	at java.awt.AWTEventMulticaster.windowClosing(AWTEventMulticaster.java:349)
	at java.awt.AWTEventMulticaster.windowClosing(AWTEventMulticaster.java:349)
	at java.awt.Window.processWindowEvent(Window.java:2054)
	at javax.swing.JFrame.processWindowEvent(JFrame.java:305)
	at java.awt.Window.processEvent(Window.java:2013)
	at java.awt.Component.dispatchEventImpl(Component.java:4897)
	at java.awt.Container.dispatchEventImpl(Container.java:2295)
	at java.awt.Window.dispatchEventImpl(Window.java:2746)
	at java.awt.Component.dispatchEvent(Component.java:4719)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:764)
	at java.awt.EventQueue.access$500(EventQueue.java:98)
	at java.awt.EventQueue$3.run(EventQueue.java:715)
	at java.awt.EventQueue$3.run(EventQueue.java:709)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:90)
	at java.awt.EventQueue$4.run(EventQueue.java:737)
	at java.awt.EventQueue$4.run(EventQueue.java:735)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:734)
	at com.intellij.ide.IdeEventQueue.f(IdeEventQueue.java:821)
	at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:649)
	at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:365)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)