I bought Season 1 of the Walking Dead through retial and I want to get 400 Days through Steam but when I get purchase this cam up: Your transaction failed because you are trying to buy 'The Walking Dead: 400 Days' which requires ownership of 'The Walking Dead'. Please correct the error and try again.
I read that I need the reciepts product code to convince Steam that I have the game but and I have it but it still said error. How can I convince Steam that I have Season 1, I'd rather not have to buy the game again on Steam. THANK YOU!