attach wheelSets to my car , the applicaition crashed!

car.Wheelset = WheelSet::createFourWheelSet(car.Body,Vector3(-3,0,3),Vector3(3,0,-3),0.25);
car.Motor = new Motor("BumperCarMotor", m_nxscene, &car.Wheelset.Drive);
car.Wheelset.attachDriveShaft(car.Motor);
car.Wheelset.addMeshes("wheel.mesh");

//////////////////
if I remove these codes,my game is OK, else,it crashed at
ogre_root->startRendering(); the failure of pointer

why?

many people can not use Motor now,is it a bug? Bejajaen?

Hi, I use this code to and it is ok for me. Except addMeshes.

i use addMesh for each wheel with my own parameters for spring.