Hello TakSeungMin.

Looks like Humble Bundle gives keys with regional restrictions.

Now you have three options:

1. You may acquire an unrestricted key/gift to give to the winner of this giveaway.
2. You may accept this giveaway as "not received".
3. You may ask us to delete this giveaway. You need the winner's permission. Please ask them if they agree to delete this giveaway.

delete it if you can, i can't join the other Dead Island giveaways cause of that :/