The key given away here was purchased from a bundle site like Otakubundle, Indiegala, Fanatical, etc. It should in theory be valid indefinite since it was legally bought but in some cases the developers of the game do not get payed by the seller or there is some other misunderstanding. This results in a good number of keys being revoked by the issuer. In most cases bundle sites cannot or will not replace these keys if they are invalid.
So please understand that if the key will not activate and report as a duplicate, I will not be able to replace it. Only enter this giveaway if you understand and accept this.