If you use Cloudflare in front of your sites, it is possible that you can run into a TOO MANY REDIRECTS error when SSL is added to your site.
This is generally caused by an incorrect setting for SSL in Cloudflare.
The Cloudflare SSL item needs to be set to FULL (STRICT) as shown in this image:
Cloudflare tends to default this setting to FLEXIBLE. Once set to FULL this issue should go away.