Thanks for the help in advance!
Depending on the capabilities of your machine and the amount of faces to intersect, it can sometimes take while. Just let it run, go make yourself some coffee or tea or something while you wait.
Very likely it is as Julian says. Lots of geometryh that SketchUp has to iterate through looking for intersections. Going off and doing something else while it chuges awat is a good option.
Another thing to consider is that you can limit the geometry the geometry that needs to be intersected. For example, if I wanted to intersect the cylinder with the railroad wheel and made SketchUp look at all 30823 faces for intersections, that would take a fair amount of time.
I know there’s a lot of faces that don’t need to be looked at.
If I select only the geometry in the neighborhood of the intersection I can limit that to less than 400 faces and greatly reduce the time the intersection takes…
If you are doing the same sort of things as before and it only just started being a problem, restart the (computer if you have not already tried that).
could you help how to limit the intersected geometry?
Turn on Hidden Geometry, drag a left to right selection box around the geometry that is needed for the intersection and then run Intersect Faces>With Selection.