I downloaded bfbc2 Vietnam ad on and it wont show up?

I updated it and restarted the game but it still wont show up.I downloaded bfbc2 Vietnam ad on and it wont show up?
if you are sharing your account with someone else, this could interfere with your add-on. sometimes you won't get stuff because that person has already downloaded the dlc onto their hard drive. then they sign out, and you won't get it. you might have it in your hdd, but doesn't mean you can use it.