When you experience a redirect loop, this can be caused by several things. On activation, Really Simple SSL adds a WordPress 301 redirect (as of 2.5.9). You can prevent this redirect from being used either by disabling it in the settings, or, if you can’t access the settings, adding
to your wp-config.php.
Another option is to activate Really Simple SSL in safe mode (as of 2.5.9). This will activate Really Simple SSL with the least possible changes.
You can try to track down the cause systematically by following these steps:
Check your certificate
In some cases a certificate with chain issues can cause issues. Check if your certificate is ok on https://ssllabs.com/ssltest. It should at least grade an A.
Something redirect back to http
If, without Really Simple SSL active, you type in the url of your website with https, and get redirected back to http, there is a redirect to http active, which will cause redirect loops when a redirect to https is added.
- Check other plugins
Multilanguage plugins, login plugins, redirect plugins, or even WooCommerce with certain settings can redirect to http.
- Check if your .htaccess or nginx.conf contains redirects to http.
If you have other redirects in place, this could conflict with the redirect of Really Simple SSL.
CDN, like CloudFlare
On your CloudFlare settings page, you should have SSL activated. Please check if you have any page rules redirecting to http.
You might need to add a page rule. The result would look like this:
It’s best to temporarily pause Cloudflare for your domain, and disable protocol rewriting to https when enabled. After successfully enabling CloudFlare, you can try if it works when you enable again.
Check if you have Varnish Cache active
Varnish often causes issues on SSL. Ask your hosting company if Varnish is active, and if they can disable it to see if that helps. With a service like www.redirect-checker.org/ you can see if your site uses Varnish Cache. If so, you should be able to deactivate Varnish in your webhosting dashboard, like CPanel.