sorry for the late reply Dan. The problem I’ve found with intersects (in my experience) is a little different from the general “ESC does nothing” issue I started this thread with. Yes, that issue occurs - ie ESC fails to abort any non-trivial intersect - but there is an additional issue that occurs occasionally where even a simple intersect (say, a line and a plane) sends rhino into an endless loop with the CPU maxed out, requiring a force quit to abort Rhino. Next time this happens I’ll attach the file, though I suspect it has more to do with the state of the Rhino application (maybe memory use, or some other specific app state) than an error in the file. I say this as in these cases, if I force quit and restart rhino, reload the file and run the same intersect, it works perfectly.