PS3: I had the same problem, I had downloaded dlc 1 but NOT free maps and when I did update 1.16 (I think) it wouldn't load the dlc maps.

Solution: I did NOT delete dlc maps instead I went and downloaded free maps first then I downloaded the "access key" only for the dlc collection 1 maps.......IT WORKS !

I'm having the same problem.  I've re-downloaded everything to no avail.  Curiously, when logged in under my sons account on the same PS3, everything is fine.  This is getting VERY frustrating.

I am on PS3. 

I have the same error after patch 1.16.  I have tried every suggestion I have seen without success including deleting Game and Save Data, "Returning the PS3 to factory default settings", and I have power cycled everything more times than I care to count since the error started last week.

Currently, I have the 1.16 Patch installed.  I have all the DLC downloaded from the In-Game Store and installed except Drop #12.  In a Private Match, I can see that I have all of the maps except for Getaway and Lookout.  That content was in Drop 12 which I was able to download at one point.  But, during the efforts to try everything which included deleting Game and Save Data, that DLC was deleted and reinstalled.  Except, that I cannot download Drop #12.  The In-Game Store returns with an error 503 most of the time and occasionally 408.

I cannot play any of the DLC maps if I am the party leader.  If someone else is the party leader, the server will let me play on the DLC maps I have already.

I tried the Support Chat applet on Saturday without success.  I went through 4 representatives before the last one gave up, copped out, and said call Sony.  The problem seems to be an Activision issue related to Patch 1.16 and the DLC.

Please help.

Thank you.

Make sure you download the FREE face-off maps also. If they are not downloaded, you will run into the error.

Had/have the same issue with the DLC message... I re- downloaded the maps .. can play they here and there ... however i have another issue (yes called the cable company) it seems (even after clearing the cashe) that there is an enormous amount of lag .. while playing  i am jumped all over the map start out running and it makes me fall off the buildings in lookout... on the new maps makes me run into walls ... on other maps it jerks me around...when running up stairs  it will jerk me back to the bottom of the stairs .. this is so furstrating !!! as we to pay ALOT of money for cable as well as for xbox 360.. any sugestions on a fix would be great !!!