Google Chrome will gradually start blocking HTTPS pages from loading insecure resources. Mixed content is content that gets loaded from both secure HTTPS and insecure HTTP connections. This change will improve user privacy and security on the web, and present a clearer browser security UX to users. Google provides a series of examples of how mixed content weakens HTTPS on its Web Fundamentals platform for developers. Users will be able to unblock some blocked content on a per-site basis “by clicking the lock icon on any https:// page and clicking Site Settings”””
Source: https://www.bleepingcomputer.com/news/google/google-chrome-to-gradually-start-blocking-mixed-content-by-default/