Hi Karlson,

I can't really tell from the image how your loft looks like. Are you using the example files included in this course? Or did you create a free from surface shape of your own? Also regarding the forces. Set all of them to 0, and then run it. If it runs, increase one force at the time to see which one gives you problems. I want to stress that unfortunately, this definition is quite specifically made for this shape (A single closed surface, close in one direction like a cylinder). It might show unexpected results if your topology is different. Nevertheless, could you share an image of the base surface you're using and I'll give it a go.

Cheers!

Arie