soysauceO3o

I am using this mod in ksp version 1.2.2. When i put the mass driver upside with a rover under it, it shows the amount of thrust it can produce but it shows no option to initiate the countdown or anything and it doesnt say anything else... i launched a small rover that could fit in it but still got no results. As stated before, this is on 1.2.2 and would appreciate the help