@Writers_Block Many thanks indeed. Unchecking the Self-collision fixed it. And well done on those videos. Very helpful.

As a followup to the previous message. Sometimes the access violation address is 00680F46, and the "Lecture de l'adresse" is 00000294.

Though I have been having good success performing cloth sims, I am unable to do any hair sims. I have been using Esidor hair on V4 in Daz Studio. I follow Biscuit’s excellent video on hair sims to the letter and all goes well until I hit the “Start Static Sim button. At that point, I consistently get an access violation message. I have attached a screen shot. Any help would be appreciated.