To see this, start the Activity Monitor by following these steps. Using the Mac Activity Monitor to see which process is “preventing sleep”Īt first I thought we’d have to go to the Mac command line to solve this problem, but then I read that you can see which processes are “preventing sleep” by using the Mac Activity Monitor application. This can happen because a programmer forget to set it back, or because the application crashed, or in the case of the example that follows, because the application was still running in the background. When this becomes a problem is when that setting doesn’t get set back to the way it was before. AirPlay and other applications do the same thing. This is what the Netflix programmers do, they tell MacOS to keep the screensaver from starting while a video is playing. One way to think of it is like this: Imagine that you’re watching Netflix on your Mac you don’t want the screensaver to kick in right in the middle of a good movie, right? As programmers, what we do is toggle a little MacOS setting that lets us keep the screensaver from starting. BackgroundĪs a small piece of background to this general problem, what’s probably happening is that there is a process (application) running on your Mac that’s preventing your screensaver from starting. Note: If you don’t care what’s causing the problem and you just want it to go away, you can try rebooting your Mac at this time. The rest of this tutorial explains the process of troubleshooting the problem, which can go way beyond AirPlay.

When we did that, the AirPlay process was automatically restarted, but when it starts running again it doesn’t interfere with the screensaver. The solution to her particular problem was to kill the AirPlay process running on her Mac. From what I can tell, after she did that AirPlay doesn’t automatically shut itself off, and it was preventing the screensaver from starting. The short story of the problem (and solution) is that she had used Apple’s AirPlay to mirror her computer screen to her AppleTV.

The same problem happened to a friend, and after a LOT of research, we were able to work through it to get her Mac screensaver working again. If you have a problem where your Mac/ macOS screensaver won’t start, I hope to be able to help you in this article.

How to get screensaver to work on mac