In 2021 a number of The Witcher 3: Wild Hunt (base game) GOG game codes were obtained from GOG by fraudulent means and sold on various game code marketplaces which we do not support. On June 8, 2021, The Witcher 3: Wild Hunt license was revoked on GOG accounts that redeemed those game codes. The remaining codes from those two series have been deactivated and won't work upon a redeem attempt.
The codes in question are 8-characters-long and start with either the letters GS or DG.
If you obtained such a game code, please contact the party from whom you got it for assistance regarding the purchase.