If you use SSL on your website and you have enabled Cloudflare, your website may go into a redirect loop.
This happens because of how the way SSL Support is configured with Cloudflare. By default, SSL connections are set to ‘Flexible’. Flexible meaning that SSL requests for your website will reach Cloudflare, and Cloudflare’s servers will attempt to fetch your website over a normal HTTP connection. If your website is configured to open up via HTTPS this can create a loop.
To resolve the issue you need to change SSL Support for your website from ‘Flexible’ to ‘Full Strict’, this way after Cloudflare receives a secure request for your site, it will use another secure request over HTTPS to fetch it from its host server.