Effects + Physics problems

Hi, I’ve started working with effects and some problems occurred.

I have a class that implements PhysicsCollisionGroupListener. I want to attach to rootNode some effects when my bullet collides in that class, but my game stops updating. I saw TestWalkingCharacter, but I can’t to the same thing, because I can’t enqueue(Callable) in that class and I want to make several effects in different locations simultaneously. Is there any similar way to do it?

Thanks for reply.