It's GMG website that is the issue. Not user error. Their system that stores your session is probably naffing up the purchase mechanic for that particular game. Because of that it will work fine for other users who haven't run into the error.
Had it happen to me for the DMC4 for a £1 deal. Could buy other games, but it wouldn't let me purchase DMC4. Contacted their CS via ticket and of course by the time they had responded the deal was over...
Had it happen to me for the DMC4 for a £1 deal. Could buy other games, but it wouldn't let me purchase DMC4. Contacted their CS via ticket and of course by the time they had responded the deal was over...