got the same Error same goes to World at War its not Funny to google alltime to a Solution and nothing will work
as last i try it with Bo2 and if its not work i will deinstall Plutonium 
then i tested all Zombies in all Games and nothing work
edit. i saw some Posts that Plutonium is on Alpha i will have an Eye on this and will redownload Plutonium soon as the Error are fixed