Well...I have raised the bullsh1t flag on this since their has been little to no help to this problem.
What I did was I loaded the game clean and then the patches.
Then I went to Multiply Player and looked at what maps it said I was missing.
Then I went are redownloaded each custom map that I was missing.
Put them in the Addon Folder on the C Drive.
Then went back to Multiply Player and low and behold it says hey...you have the freakin map.
So I select a server and it either lets me in and I can play or it gives me a message such as..."You can not enter, you do not have the map being played."
Now this is pretty much a 50/50 shot so something needs fixed...
My suggestion is a freakin AUTO DOWNLOAD like Call of Duty that way the Server Runs the show and you don't waist hours loading maps just to get some bullcrap responce from a server that you dont' have a map you just downloaded.
This also happens on Custom Maps that only have 1 version not multi-versions so that excuse is out to.
"You will learn your place my young padawan."