If you are proxying traffic to a Wordpress website running on Cloudflare you may come across the following error message when visiting the Wordpress admin area for your website (/wp-login.php or /wp-admin):

ERR_TOO_MANY_REDIRECTS

Your can fix this error by logging into your Cloudflare control panel and clicking on "SSL/TLS" down the left side of the page and then changing the encryption mode to either "Full" or "Full (strict)".

More details on the various Cloudflare encryption methods that are available can be found here:

https://developers.cloudflare.com/ssl/origin-configuration/ssl-modes/