I don't know but it's been happening to me too since saturday. The game 'lost' my saves (
http://www.telltalegames.com/forums/...ad.php?t=29343) so I backed them up, uninstalled, grabbed latest from telltale (WalkingDead100_v2_Setup.exe), installed. Then as above, nothing. Even if you enter random stuff into the login
Lost saves, no activation
Late edit: I got it working but I can't really say how for fear of ban. Lets just say the absence of DRM makes this issue moot. I suspect there is a problem with the v2 setup you get from the telltale site, but with silence being the only response I'm not sure what else us paying customers are supposed to do. I'd like to extend my thanks to the fellow community members who figured out how saves could be restored.
I don't regret the purchase as I love the game, but it's a bit depressing to be using such extremes just to play it