Buying modern warfare again even though I have it

I've seen this be a problem with other peoples games. I've seen that they've re downloaded the multiplayer pack and it fixed it! Let me know if this does.

I was gonna buy Modern Warfare 3 on the PC even though I have Battlefield on Xbox. I got as far as the counter at the Game store, then I thought how crazy it was and got Modern Warfare on the Xbox. I often lie awake at night wondering to myself what life
would be like if I had the guts to go with the PC version.

You do not understand the issue, you have to understand that there is modern warfare (not free) and modern warfare war zone (free)

For those who have a physical version, we can't access the original modern warfare campaign and other stuff from the main game that we purchased, we can only access modern warfare war zone, everytime we try to play the original modern warfare and not modern
warfare war zone it tell us that we have to purchase it. Even though we had paid for the physical version already.

Even though you just played modern warfare 2...

Haven't even considered buying Modern Warfare 3 so it's a no brainer for me.