Well then it’s most likely a problem on your origin.
The top reasons for this error are:
- Permission rules you have set or an error in the .htaccess rules you have set.
- Mod_security rules.
- IP Deny rules
Since Cloudflare can not access your server directly, please contact your hosting provider for assistance with resolving 403 errors and fixing rules. You should make sure that Cloudflare’s IPs aren’t being blocked.