I've searched. I'm sure it's obvious or that there's been topics on it, but I can't find them... Maybe I'm just tired... Got a dual processor box. Know that Bryce (5.5) isn't multi threaded enough to take advantage of this. Want to run Bryce Lightning on same box. How do I get the Bryce UI plus Lightning to render? At the moment I can only get Lightning to do it, and not the UI. Where's the setting I've missed? Where's the message saying it's been removed? Sorry for being dumb! All the best, Mark.