I'm having some trouble with this mod, I am able to set the centre of mass. After launch, the marker shows that the CoM has moved, but the error is always reported as 0, and the fuel is not moved around when its told to balance. I have tried this on two saves, here is a persistent save that has a ship with the issue. (Only ship in the save) Mods I am also using: Editor Extensions, Engineer Redux, KAS, Kethane, Protractor, RCS Build Aid, & Kerbal Alarm Clock. I checked the log, there were no noticeable errors. Edit: After further testing I think I have solved the mystery. It seems the balancer only activates after it staged? Depending which stage I am in, it will suddenly activate, and start displaying the CoM error. There doesn't seem to be any way to control at which stage it starts reporting the CoM error. I think it only turns on on the very last stage.