In Snoopy's Street Fair, you have the option of adding Game Center or Facebook friends' fairs so that you can share things like trading cards with them.
I have a friend on Game Center who I know is playing Snoopy's Street Fair, however every time I try to add them using the "add friend's fairs" button (and selecting the "use Game Center" option), it always says "0 Friends added" and I can't visit their fair.
Why is this happening? How can I fix it? I don't want to be friendless forever!