All of a sudden Buffalo now requires me to enter my serial # to download anything from their site. I downloaded something less than a week ago and did not have to.
I try putting in my serial #, but it keeps telling me it's invalid.
I believe Buffalo has been having some issues w/ downloads lately...
But anyhow, if you are at the correct Buffalo download site for your region (i.e. North America, Europe, etc), and it's not working, your best bet is to contact Buffalo support.
Alternatively, the forum Mods might be able to assist you, but your best bet is to contact support if you require the download immediately.