Hi :) I had the same problem and contacted CL , They told me that its not a bug , but the simulator is getting confused , and If in the pose/animation the cloth gets squashed between 2 body parts it will confuse the simulator and stop ,In my test I was using a walk cycle and when the arms swing past the chest the cloth was being squashed between the arms and chest , adjusting the arm swing so that the arms swing out a bit more fixed the problem :) i have noticed that when using it with poses it also happens that some body parts come in contact with other body parts in the transitions before the final pose , justing these contact areas so they give the cloth room to move has also fixed these situations:) I hope this Helps :) Cheers Senyac