Tracer96

I redownloaded, and still got 4212 Liquid Fuel. Oxidizer was similarly out of whack. This is the only stage that is causing issues. I think it has something to do with your 64K config. That lists the Liquid fuel at 4212 units and oxidizer at 5148. . It is missing something in the config too. " @PART[KK_SPX_F91_S2tank] { @mass = 4 @RESOURCE[LiquidFuel] { @amount = 4212 @maxAmount = 4212 } @RESOURCE[Oxidizer] { @amount = 5148 @maxAmount = 5148 } } " It lacks the term NEEDS[64K]

Just so you know, the Falcon 9 V1.0 upper stage has something like 4000 liquid fuel. The rocket barely gets off the ground.