Causes

• A web request was sent to a Cloudflare IP address for a non-existent Cloudflare domain.
• The target of the DNS CNAME record does not resolve.
• A CNAME record in your Cloudflare DNS app requires resolution via a DNS provider that is currently offline.
• always Online is enabled for a Custom Hostname (SSL for SaaS) domain.

Fixes

Step 1

A non-Cloudflare domain cannot CNAME to a Cloudflare domain unless the non-Cloudflare domain is added to a Cloudflare account.

Step 2

Attempting to directly access DNS records used for Cloudflare CNAME setups also causes error 1001 (For example: www.example.com.cdn.cloudflare.net).

Step 3

Disable “Always Online” if using Custom Hostnames (SSL for SaaS).