Plutonium

why do i have to buy ? the other people don't have to , is it a specific problem ?

hello me and my friend have a problem, we can't play on DLC zombies map , we can see the dlc map but we don't see the picture of the map it just show green and orange squares and when we start the game its not loading it just show the name of the map with the squares a mention and the loading bar is not loading, i read that we don't have to buy it so if you can answer it will be nice thank you.