when I launched ksp after 6 months, the 5m parts had Z fighting so I went through your troubleshooting check list, I was halfway through the list when I managed to delete the entire Game Data file, after reinstalling the Game Data folder and my mods(DMagicOrbital Science, KJR, MechJeb, MRS, LET Space Y, Space Y Expanded, TweackScale, Community Tech Tree, and Interstellar Fuel Switch). KSP won't load the Heavy lifter parts pack, but loads the Expanded parts. I have tried a clean install of both mods.