Try uninstalling Firefox to see if that fixes your flicking problem.
#Show a movie in screen saver mac pro
![show a movie in screen saver mac show a movie in screen saver mac](https://i.pinimg.com/originals/19/aa/ec/19aaec293aa60930bb8a8ce3c272efb5.jpg)
![show a movie in screen saver mac show a movie in screen saver mac](https://download-screensavers.biz/images/video-screensaver-mac-os-lion-3.jpg)
Here is what you can do if your Mac screen is flashing or flickering: Screen flickering issue, fixes Mac screen flickering can be caused by different issues.