A really trippy bug, that doesn't seem to originate in my code

General Discussion
1

I’ve been having a problem, were occasionally my game crashes while loading, giving the stack trace

java.lang.NullPointerException
	at com.bulletphysics.collision.broadphase.DbvtBroadphase.setAabb(DbvtBroadphase.java:203)
	at com.bulletphysics.collision.dispatch.CollisionWorld.updateSingleAabb(CollisionWorld.java:222)
	at com.bulletphysics.collision.dispatch.CollisionWorld.updateAabbs(CollisionWorld.java:247)
	at com.bulletphysics.collision.dispatch.CollisionWorld.performDiscreteCollisionDetection(CollisionWorld.java:135)
	at com.bulletphysics.dynamics.DiscreteDynamicsWorld.internalSingleStepSimulation(DiscreteDynamicsWorld.java:378)
	at com.bulletphysics.dynamics.DiscreteDynamicsWorld.stepSimulation(DiscreteDynamicsWorld.java:339)
	at com.jme3.bullet.PhysicsSpace.update(PhysicsSpace.java:330)
	at com.jme3.bullet.PhysicsSpace.update(PhysicsSpace.java:317)
	at com.jme3.bullet.BulletAppState.render(BulletAppState.java:257)
	at com.jme3.app.state.AppStateManager.render(AppStateManager.java:300)
	at com.jme3.app.SimpleApplication.update(SimpleApplication.java:251)
	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)

If you look at that exception, it doesn’t come from my code! Is their a problem with JMonkey? Did I break it? Am I handling something wrong?

2

You’re probably adding or removing an object twice from the physics space. Otherwise, given that you say its occasional it might also be a threading issue where you add an object to the physics space from another thread.