My app is random crashing for no reason apparently because of nifty , this is the error :
SEVERE: Uncaught exception thrown in Thread[LWJGL Renderer Thread,5,main]
java.lang.NullPointerException
at de.lessvoid.nifty.screen.Screen.forwardMouseEventToLayers(Screen.java:352)
at de.lessvoid.nifty.screen.Screen.mouseEvent(Screen.java:339)
at de.lessvoid.nifty.Nifty.forwardMouseEventToScreen(Nifty.java:308)
at de.lessvoid.nifty.Nifty.access$1600(Nifty.java:77)
at de.lessvoid.nifty.Nifty$NiftyInputConsumerImpl.processEvent(Nifty.java:1373)
at de.lessvoid.nifty.Nifty$NiftyInputConsumerImpl.processMouseEvent(Nifty.java:1329)
at com.jme3.niftygui.InputSystemJme.handleMouseEvent(InputSystemJme.java:169)
at com.jme3.niftygui.InputSystemJme.onMouseButtonEventQueued(InputSystemJme.java:232)
at com.jme3.niftygui.InputSystemJme.forwardEvents(InputSystemJme.java:296)
at de.lessvoid.nifty.Nifty.update(Nifty.java:288)
at com.jme3.niftygui.InputSystemJme.endInput(InputSystemJme.java:113)
at com.jme3.input.InputManager.processQueue(InputManager.java:819)
at com.jme3.input.InputManager.update(InputManager.java:883)
at com.jme3.app.Application.update(Application.java:604)
at com.jme3.app.SimpleApplication.update(SimpleApplication.java:231)
at com.jme3.system.lwjgl.LwjglAbstractDisplay.runLoop(LwjglAbstractDisplay.java:151)
at com.jme3.system.lwjgl.LwjglDisplay.runLoop(LwjglDisplay.java:185)
at com.jme3.system.lwjgl.LwjglAbstractDisplay.run(LwjglAbstractDisplay.java:228)
at java.lang.Thread.run(Thread.java:744)
Do anyone else get this error and know now to fix it ?