Omg yeah that's what I was doing and I spent a week already fixing things :dry: I've tried this route on CK but i can only generate precombine for the commonwealth world, there is no option to generate previs for the whole commonwealth. Thank you for the VC and timestamp info that would really help me. What I'm trying to accomplish is make precombines and previs for a merge patch containing mods such as beantown interiors project, boston natural surroundings and other mods that had added something to the commonwealth world. So that I'll have a near perfect fallout (spent a lot of time tweaking and fiddling trying to fix my load order to make it perfect, compared to my actual play time). What I figured was, have a merge file of all these records then use CK and not the cli to generate the precombines. My belief is that CK would be more stable this way and will be forced to regenerate everything and retain everything? :pinch: What would be the best approach to attain my goal? Should I just merge BT_interiors and BNS then generate precombines and previs on cli?