There was a call Of Duty Modern Warfare 3 giant update and it deleted a bunch of important files or changed the .exe and other files I need for the Plutonium mod to work, thankfully I can still play MW2, WAW and BO2 (But I had to update the entire IW4X using the IW4X launcher and that overwrote files but MW3, isnt working.
Error files and file problems 'AIL_set_redist_directory@4 from module 'mss32.dll'
Possibly that mss32.dll needs updating perhaps.