1) delete the folder for fallout 4, then let steam re-install it With that many broken mods this is your only safe option 2) I don't know which mod organizer you are using but the ONLY one i suggest is NMM, (nexus mod manager), which is still being updated by an outside team Located here for download - https://github.com/Nexus-Mods/Nexus-Mod-Manager As for instructions, here ya go, below, - Ignore what Gopher says about where to download it ( use the link i provided ) , Nexus has moved on to Vortex, which I do NOT recommend You might want to watch episode 2 of that by Gopher also, i think it will explain a lot to you :)