Hi!
I have seen a couple of posts with the same problem as me, but couldn't find the answer. When I use the NERVA engine, it contain EnUr. If I try to swap fuels, then the fuel slider disappears. This happens with a few other engines: "Solid core nuclear Engine", "Tory" and the "Direct cycle nuclear turboengine".
I am using KSP 1.12.5 (although I have also tryed KSP 1.11.2 with the same result) and the latest KSP-IE (1.29.6) and Interstellar Fuel Switch (3.30). I don't have other mods, other than the ones recommended or required for KSP-IE
Can someone help me? Thanks!