403 Forbidden Error with Custom Domain Using a Reverse Proxy
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Overview
This article explains a potential cause for a 403 Forbidden Cloudflare error when attempting to access a custom domain that uses Self-Managed certificates behind a reverse proxy.
- When using the try button, the following error may occur: Error! Looks like your domain is not configured correctly. Please check your reverse proxy configuration.
Applies To
- Custom Domains
- Self-Managed Certificates
- Reverse Proxy
Cause
A possible cause for the 403 error is that the reverse proxy is not using the Origin domain name, which was assigned during the custom domain setup, as the host header.
Solution
To resolve this issue, ensure that the reverse proxy configuration is set to use the Origin domain name from the custom domain settings as the host header. The correct value can be copied from the tenant dashboard under the Custom Domain Settings section.
