I also had CTD while 1st stage separation I looked through scenarios and ini files and find out that scenarios point to Config/Space-X_lunchers and ini points to Config/Space-X_rockets, I think that easyiest way is to copy Space-X_lunchers and rename it to Space-X_rockets and have bouth folders...
I was loocking for MSFS addons 4 or 5 years ago and googled Orbiter by accident, I fought "It cant be real sim, propably not working" but I gave it a try and I dont regret it :)