I use Linux (Fedora) now and sometimes one update messes up things, so I need to fix them. I often can’t see videos right or some web pages show up with missing elements. Not anymore since I got a fix.
1. Open a new tab.
2. Type in the address bar “about:config”
3. Click on “I’ll be careful, I promise”
5. Close the tab. Issue resolved. Mission accomplished 🙂