So I recently tried the free trial of Unraid, and when the trial ended I bought the basic version. I redownloaded the os to the same drive, and when I redeemed the code, it showed an error, then I went back to the dashboard and tired to retry it but now it says the drive is either blacklisted or already has a key. I have tried to redeem it on a different drive, but it said it already was redeemed.

 

Try mark down disk assignment, then perform new config and redeemed again.

Activation is one-time only, if you are using the same flash drive you just need to re-install the key, use the URL you got by email on Tools -> Registartion, if you are using a different flash drive or still have issues contact support.