Error: DOMAINNAME is not a valid domain. Please add it to the cookie consent manager to authorize the domain.

If an error message saying "Error: DOMAINNAME is not a valid domain. Please add it to the cookie consent manager to authorize the domain." appears in the browser's developer console, please see this article for explanations and solutions: Error: The domain is not authorized to show the cookie declaration. Please add it in the cookie manager to authorize the domain.