Hi Sharif, could you possibly simplify your file to contain just 1 surface and 1 curve that you want to cut it with? That would help to make it easier to understand what you are trying to do there.

One thing to note is that to cut a surface with a curve, the curve has to fully divide the surface into separate pieces.

For example here is a plane and a line, the plane cannot be trimmed by the line because it does not clearly divide the plane into different pieces:



Here I have enlarged the line somewhat, so that maybe it kind of looks like it would almost divide the plane, however it actually still does not divide it and will still have the exact same problem as above:



You may be running into something like that.

- Michael