Xbox Live Gold and Game Purchase

You can "purchase" the current Xbox 360 Games with Gold for free here:
http://www.xbox.com/live/games-with-gold

So you went to purchase a gift code for Xbox Live, and in the purchase for you it gave you an error?

Is this the link you are using to make a purchase: Buy Xbox Live Gold — Xbox Live Gold 1 Month | Xbox

and are you choosing the "Give as a gift" option?

Or are you using this link: Buy Xbox Live Gold Membership (Digital Code) - Microsoft Store and its giving you a purchase error?

Thank you,

Xbox LIVE Rewards is a loyalty program that rewards members for renewing their Xbox LIVE Gold subscriptions, playing games, engaging with Xbox LIVE features, making purchases from the Xbox LIVE Marketplace etc... and a gold member does mean a xbox live gold
member.

Seems like the issue is not regarding to your game edition it is due to your subscription. The game requires Xbox Live Gold subscription to play it. It’s either you will purchase Xbox Live Gold subscription or Xbox Game Pass Ultimate since the Ultimate included Xbox Live Gold as well.

when you purchase a free "Games With Gold" game on xbox 360, you get the license permanently, even if your xbox live gold subscription expires.

on xbox one, you can also access all of your free purchased Games With Gold (they are all Backwards Compatible), however you need to have an active xbox live gold subscription to be able to play them.

if you are currently not subscribed to a gold account, then all you would have to do is re-subscribe and you will have access to any of the Games With Gold games you have previously purchased.