Hi Jacob,
Thank you for posting the query on Microsoft Community.
Sorry to know that you are unable to redeem a code. I would like to ask you:
- Which browser are you using?
Try with a different browser and check if it helps.
If it does not work. sign out from the Microsoft account and log in again and then try.
If you are using Store, then run the Windows Store Apps troubleshooter.
If the issue persists, then you need to check with Gigantic support.
In future, if you have any issues related to Windows, do get back to us. We will be happy to assist you.