[1.12.3] Bluedog Design Bureau - Stockalike Saturn, Apollo, and more! (v1.10.4 "Луна" 19/July/2022) in Add-on Releases Posted October 10, 2021 1 hour ago, CobaltWolf said: I wonder if it's because it has solid fuel now as well? @Jsoany insight? Do I need to separate the solids or something? Yes. Any part with a ModuleEngines gets bypassed by the fuel switcher patch, because the fuel is assumed to be for the engine.