when i try load into modded lobby mode i crash

Deaglerr

it downloads mod seemingly ok then when it shows me the desktop and tries to go back into mw3 it crashes

hindercanrun

Cannot join servers with mods (game window never starting)
Stay in the main menu or close your game if you're already stuck without the game window opened.
Open a command prompt (cmd) in Windows and paste this command (right click) rmdir /s /q %localappdata%\Plutonium\storage\iw5\mods then press Enter

Until Plutonium fixes that issue you'll have to do that when the issue occurs.