Redirect issue with Really Simple SSL and multisite
The Really Simple SSL plugin is, as the name suggests, a really simple way to move your sites over to HTTPS. If you have an open source certificate like Let’s Encrypt, it’s also very affordable…
I’ve recently switched a number of sites over to HTTPS using Really Simple SSL. For the most part, everything went very smoothly but I ran into one problem when moving a multisite installation across. For the record, the installation was subdirectory rather than subdomain, though I don’t think that was the issue.
After installing and activating the plugin on a subsite, I tested the front end and received the ‘Too many redirects’ error message, meaning the page wouldn’t load. I tried a couple of the Really Simple SSL settings without any effect, checked that WPML wasn’t running as apparently that can cause problems, and read through the checklist here: https://really-simple-ssl.com/knowledge-base/my-website-is-in-a-redirect-loop/
I then realised that the site was running the WPMU Domain Mapping plugin which, since WordPress 4.5, is redundant as far as I can see. So I disabled the plugin and followed the article here – Mapping a domain on WordPress 4.5+ Multisite. That cleared the redirect loop.
Thank you very much for this article. We’re working on adding SSL to our Multisite and had the same issues with the redirect errors. Disabling the WPMU domain mapping and applying the domain change through the Site Address (URL) worked well.