If you have Sucuri’s Firewall enabled, they have SSL. I had trouble getting my site to be secure, as the https:// would cause a redirection error. Turns out I needed 2 simple things:
- Really Simple SSL plugin, just install, activate, and one-click to make all pages go from http:// to https://
- Change your Siteurl and Home to https://
After that, the site came up instead of showing a full screen error.
Of course, there were mixed content errors, so I fixed them.
Note: See also Tips for Moving a Site.