Did you register using Google or Microsoft Sign Up and now that email address has changed?
As long as you still can receive emails on the original email address there is a solution.
1. Generate a password for your old email address by clicking the "Forgot Password" button on the Login page.
2. When the new password is set and you are logged in, go to Settings → Profile and change the email to your new Google or Microsoft email address.
After the email is updated you can log in using Google or Microsoft and your new email address.