ERROR WHEN ITETATING in dynamic mesh
 

Hi The case i am working on is in cylinder flow without combustion, i have defined dynamic mesh for motion of piston. and for the valve, i have used EVENTs, just changing the boundary type and zone deactivation/activation. but when the angle reaches the value to change the BC, an "access violation" error accurs, and the iterations stops. i have checked the BC, and... and i am sure they're right and the problem is well-posed. please help me. As another problem, other errors occur in the second cycle of piston motion. thanks so much and i am waiting for the answer.