You may have recently closed your AdSense account or received an email email@example.com about your AdSense application being disapproved. Without a valid AdSense account, you cannot participate in YouTube's monetization programs.
Relinking may take 48 hours to process and remember you must enable access for YouTube in your new AdSense account. Once you've associated a new account, you will receive an email from firstname.lastname@example.org titled "Google AdSenseAccess Verification for www.youtube.com" to remind you to enable access.
The YouTube Team