December 13, 2017
I’ve run into a couple of issues where a website will break due to the site being SSL secured but the stylesheet refusing to load as SSL.
This becomes especially problematic if SSL is added to the website as an afterthought (e.g., if a store is added later on, and the website URLs are changes to https).
There is a great plugin call SSL Insecure Content Fixer than can help fix discrepancies in your setup, and ensure that your stylesheets always load correctly.
You can read more about this issue, and alternative solutions here on Stack Exchange.