Beta code not working..

I got my code earlier today and tried entering it into steam 4 times, but kept getting an error each time.

Error: "Purchase error. An unexpected error has occurred. Your subscription to the following item has not been completed."

I made sure the account I'm using is the correct one. What can be done?

Hey! Closed Beta ended few days ago.

Now the game is in Early Access. You can buy it for $19.99/€19.99 (or your regional equivalent). Check it out on Steam. 🙂