If you've encountered the error ResolverRequiredWhenDataSupplied the solution may be as simple as refresh and try again, or clearing the sites browser data.
Solution:
First try disconnecting your wallet, close the page, then reopen Manager App (app.ens.domains), reconnect your wallet, and try again.
If the error continues, clear your browser cache & cookies for the Manager App (app.ens.domains), reconnect your wallet, and restart the registration process.