- The CNAME hasn't been set up correctly. This can be checked by running the domain through https://www.dnswatch.info/ and getting a response where the CNAME is not pointing to www.cmsappbuilder.com
- The CNAME is correct only you've entered the wrong Custom Domain in the Reseller Settings. In the Custom Domain field, enter your custom URL (without http://) The Subdomain field can be left empty.