That would be pretty much the same issue I was noting earlier. Reactor upgrades, at least for the magnetic confinement fusion reactor and the antimatter-initiated fusion reactor do not seem to be working. They show up on the tech tree just fine, but purchasing them does not, in fact, give you access to the upgraded reactors. You can sidestep this on the magnetic confinement reactor by viewing parts by tech level, as they show up under "level 9", there, but I haven't found any way at all to access the upgraded antimatter-initiated reactors. Additionally, the High-Q and Ultra-Q reactors don't seem to function, even if you do pick them off the level 9 tech list--both will endlessly give you the warning about needing to reduce power requirements and not produce power for your generator or attached engine. Thanks for confirming to me that this isn't just an isolated problem only I am experiencing. I've been trying everything I could think of with changing out mods/reinstalling the program to fix it over the past month or so.