Humble Jumbo Bundle

Humble Bundle Store sucks, gifting sometimes gets screwed up. I never buy gifts there anymore.

I get the same message when someone redeems the gift link before I do, maybe you did something wrong.

This is what I do buy it then there's a present next to the game names and you click that and you get a link to send to a friend try doing that instead

why not jsut buy the bundle for yourself? then link him to it? sounds safer to me

Before, I got the same message when I submitted my friend's email address for the first time.
In our case, he managed to get the link using Humble Bundle Key Resender that you can see as "Lost Key" at the bottom of the site.

[Edit]
Using Humble Bundle Key Resender, you receive all links you redeemed before.
If the Humble Jumbo Bundle link isn't in the resending email, maybe the link went nowhere.
In that case, I recommend you contact support.