Really Simple SSL first tests if a redirect rule works, before actually adding it to your .htaccess. So if it is added, your server seems to supports it. That you are experiencing a redirect loop would suggest there is a conflict with another plugin, or with something in your .htaccess files.
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.
Check other plugins
Multilanguage plugins do a lot of redirects to get your visitor to the right language. Try re-saving the settings of your language plugin, or try what happens if you disable it. If you cannot access the admin as well, the easiest way to disable a plugin when you have a redirect loop, is to rename the plugin folder through FTP. But in most cases when a plugin causes a redirect conflict, you can still access the back-end.
Redirection plugins, security plugins and caching plugins might cause redirects as well: deactivate them to see if this helps. If that plugins redirects to a http link, obviously that will cause redirect issues. Update it so it redirects to the new https url.
CDN, like CloudFlare
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 your .htaccess contains other redirects to https.
If you have other redirects in place, this could conflict with the redirect of Really Simple SSL. If you are using NGINX, check your nginx.conf for conflicting redirects.
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.
Remove .htaccess redirect
If you are on NGINX, you can skip this step.
If the other steps didn’t help, you can try to remove the rewrite rule from your .htaccess file.
- Open your ftp client (for example filezilla)
- In the root of your website, look for the .htaccess file. If you cannot find it, make sure filezilla shows hidden files
- Open it in a texteditor, and look for # BEGIN rlrssslReallySimpleSSL
- Remove all lines between # BEGIN and # END, and save
- Prevent Really Simple SSL from editing the htaccess any further:
- Look for wp-config.php in the root of your site.
- Open the wp-config, and add at the top, but after “
define( 'RLRSSSL_DO_NOT_EDIT_HTACCESS', TRUE );
- Alternatively, if you have still access to the backend, you can disable .htaccess editing in the Really Simple SSL settings