I have created a very complex map in Illustrator. I am trying to cut out smaller areas of the map for use in other SketchUp. Neither pathfinder nor Divide Below gives me predicted results. I turn off layers I don't need, then flatten the whole thing which gets rid of alot of stuff. The resulting file is not that complicated. I then draw a square (1-point stroke, no fill). I want to keep everything inside the square get rid of everything outside. When I perform Pathfinder > Divide I get a big mess that makes no sense. Divide Below doesn't seem to work either.
Pathfinder doesn't understand strokes very well.
Set your rectangle to a solid fill and no stroke.
Then select the rectangle and artwork and click the Crop button on the