Trouble playing co-op

Hey there! My boyfriend and I just bought Diablo 3 on our own xbox consoles so we can play together yet this seems to have been a problem in the past, when inviting each other to our games, we're like level 3, it keeps saying error joining the game. Yet
we put to the setting to off region override and stuff, still wont work. I've read the Blizzard forums that you have to restart the router and the NAT stuff yap yap yap. Yet people have tried that and multiple other things yet nothing worked. But those posts
are from like september 2013.....9 months ago. I'm surprised this is still a problem so I was wondering if there was another solution for this annoying issue. So any tips would be awesome. Thanks :3

:)

 

15 hours to download a game?

5MB, download pretty much faster on xbox360 and no trouble playing co-op and/or multiplayer on xbox live.

 

Co-Op Playing

I'm up for some co-op as well, as soon as I get my Gold back I will play!