Site doesn't come up when "www" is included in the URL

Typically, this issue is due to a missing DNS record, and is easily fixable.

Solution:

• Sign into your domain registrar account (wherever you manage your DNS records)
• Create a CNAME record for the 'www' host, and point it at your main domain. Depending on your DNS provider, they may want you to enter the domain itself as the "value", i.e. mywebsite.com, or they may want you to enter "@", which is a type of shorthand for the main domain.