Hi Eddi, I can also produce the chamfer problems over here as well.

But unfortunately those are quite difficult for me to fix. I will gather these up and send them to the people who make the geometry library that I'm using and they should be able to fix them up over time, but it will be a kind of slow process. In general fillets and chamfers are a very complex area. In this case there appears to be a problem with some of the slight curvature of the side surfaces as they meet up in a sharp corner. Sometimes things meeting up where they are close to being tangent but not quite can cause difficult calculations.

But the loft one I could probably fix up right away if I had a good example to reproduce it from the original curves, that's why I was particularly interested in that.

Sometimes a bug is caused by some very specific arrangement of curves, like endpoints in particular spots or things slightly twisted from one another. That can make it difficult to try and reproduce the problem just by drawing something new.

- Michael