How do I fix "This code was purchased in a different region" error?

This error means your game key is region-locked to a different country than your Microsoft account. To fix it: 1) Download https://www.opera.com/download Opera browser (it has a free built-in VPN). 2) Enable the VPN in Opera settings and select the region matching your key. 3) Go to https://account.microsoft.com/profile and change your country/region to match the key. 4) Redeem at https://redeem.microsoft.com. You can change your region back after — your game stays on your account.