TheBigGoomba101 try to let it load for some minutes if you have a slow disk.
Otherwise you can try this
Make sure your game is closed before doing that.
Go to %localappdata%\Plutonium\storage\t4\players
Open the config file with the notepad to edit it.
plutonium.cfg is for singleplayer/zombies and plutonium_mp.cfg is for multiplayer
Change these 4 dvars to be like below (you can use ctrl+f to search for them)
If this still doesn't work then show how the mod is installed, the folder and its content, show everything.
Also are you using your Steam files?