SSL Mixed Content Resolution
In some cases, WordPress or it's themes/plugins may get confused regarding what protocol it is working on. Internally, your WordPress installation will work as "HTTP" unencrypted.
  • Then later, StackOS will automatically encrypt your traffic.
This is where the problem starts. Your WordPress and Plugins (such as Brizy) ask the browser to load new programs/content over HTTP.
However, remember that the actual content is encrypted for you, and thus the browser is actually operating in HTTPS encrypted mode.
When your browser in HTTPS mode is requested to load new content (Images, JS, CSS) over HTTP, to protect you, all those "mixed-content" loads are canceled. This makes it look like your site is broken.
You might even just see a broken loading screen like this:
Or you may see broken images like this:
Technically WordPress and all Themes/Plugins should auto-adjust, however since there are so many themes/plugins that are not aware of protocol changes, then often sites break. This doesn't mean your StackOS installation has failed. In fact everything is operating exactly as designed. It's just the design that is incomplete. To patch this issue, there are a few items to look at. Your site logo and favicon must be uploaded (you should not use the default)
For theme/plugin mixed-content issues consider: You'll install the plugin, configure it, but ignore a few steps. If you get this error:
Be sure you followed these steps noted previouslyStackOS Wordpress - Upload limit increase (external) This is enough to get WordPress and some plugins/theme's to be adjusted for HTTPS mode. For example, install a plugin like Brizy (This is just an example. Your plugins may behave differently depending on how they were written)

Now install Really Simple SSL to fix most mixed-content issues

Note: If you do not "Check" the Override SSL Detection option, then you will go through the steps off issuing an SSL certificate. That is fine, but there will be no need to install the resulting certificate since StackOS has already handled that process for you in advance.

Verify https is now set in your Settings > General

Experiment with a page edit with your plugin/Brizy