Thanks for the reply. I did use Ckan to install, followed a vid on youtube from Carnasa. The only thing I installed manually was Principia because it's not on Ckan. Everything works OK ( as far as I can tell, I just started playing ) except those early big liquid engines. I put the rocket on the pad in a launch clamp, go full throttle and stage... then the throttle goes to zero and no engine ignition. If I stage again the clamp releases and the solids lift me off but still no light on the liquid engine, and then I crash. I modified those engine configs and commented out the "literalZeroIgnitions" line and gave myself 1 ignition for those engines. Even with that change the same thing happens when on the pad in the clamp, no lighting and a drop in throttle to zero, but at least when I stage to release the clamp and light the solids, then the liquid engine ignites and seems to work normally. I'd rather use it as intended but I never get an early liquid engine to light with any launch clamp. Any ideas on why this could be happening or if I'm doing anything wrong would be great.