Hi AlexPolo.

You are referring to the Green objects ?

Have you tried to select all Green objects and perform a "intersect" command to try to see what's going on ?

Hi Alex, your boolean succeeds over here, does it work for you if you reload the file?

When many objects meet at a single crown point like that it needs some special handling in the intersection process, it's a pretty complex thing not really what I'd call a simple case.

- Michael

Hi - I copied items into new screen and BOOLEAN aok - not sure why in parent model not working

thanks again.

Hi Alex, well it's probably a bug of some sort, but it's very difficult to figure out what went wrong when it's not repeatable.

- Michael