Mixed Content Errors are usually created by having the WordPress installation incorrectly configured to match the correct HTTPS protocol.
If a WordPress website has Mixed Content errors, Images, Icons, and Custom Fonts will not be loaded correctly.
This usually happens when:
The website is moved from a staging domain (which uses HTTP) to a live domain where a valid SSL certificate is used
The SLL certificate was installed after WordPress was installed
Install and Activate the Really Simple SSL plugin (easy)
Go to WordPress Dashboard → Plugins → Add New
Search for Really Simple SSL plugin
Click on the Install button
Click on Activate button
Install and Activate the Better Search and Replace plugin (advanced)
Important Note:
It's always recommended to create a full backup before making any changes to your database. To do so, follow the How to Take a Backup of Your Website guide.
Go to WordPress Dashboard → Plugins → Add New
Search for Better Search and Replace plugin
Click on the Install button
Click on Activate button
From the left Sidebar, click on the Better Search Replace option
In the Search For field, type in your website URL with HTTP(e.g. http://domain.com)
In the Replace With field, type in your website URL with HTTPS(e.g. https://domain.com)
In the Select Tables option, select all of your Database Tables
Uncheck the Run as dry run option
