A mixed content warning appears in a user’s browser when the WordPress site is trying to load both HTTPS and HTTP content (e.g. images, forms) or scripts (e.g. analytics tags, youtube videos) at the same time. You can’t load both as they are completely separate protocols.
The user’s web browser may display an error if this is present and therefore a website administrator needs to fix this. The solutions are fairly simple, and below is a great article on how to diagnose and fix these:
If you run into any trouble, please request help and we’ll be in touch.