The fully qualified domain name (FQDN) must be between 3 and 254 characters long, and must have fewer than 64 characters ...

The fully qualified domain name (FQDN) must be between 3 and 254 characters long, and must have fewer than 64 characters in each part. For example, for www.contoso.com, there are a total of 15 characters and the longest address part, contoso, is 7 characters. {0} doesn't meet that requirement.