The cause of your problem can be that the region code of your game is different compared to the region code of your dlc.
if this is not the case then try to re-download it from the PSN store.
If that is also not working then it could be an error of Infinity Ward.
They'll release a patch for it then, if not, then you should contact the local Infinity Ward customer service.
Hope this info works for u.
Greetz Quinten
I had this happen. I tried a wired & wireless portal with the same issue. I reset the game a few times to get it going. I don't think it is a portal issue but rather an issue with the (Wii) game itself.
Here is a link to the Sony webpage explaining how to deactivate your games on all systems, including those not in your hands.https://support.us.playstation.com/app/answers/detail/a_id/2616
This can only be done once every 6 months. You will then need to reactivate the system you want to still use.
To deactivate video on a system not in your hands, you have to contact Sony Customer Service: 1-800-345-SONY (7669).