First thing I would do is reinstall Nexus. Second: Sometimes you get overwrites of the .ini files in the documents folder on the C: drive. Just delete the .ini files and try the game, if it starts, it will rebuild the .ini files. I am guessing that you do not have your games on Steam. If you do, you can run a file integrity check. Reinstall Nexus. It may act as a fresh install. You may have to reinstall all your mods. You may have to reinstall the Skyrim game. Same goes for Oblivi