The only way of confirming what happened is to browse the log – and that’s not easy. Could it be malware perhaps? It’s probably wisest to make sure your work is saved at that stage, close your apps down in an orderly fashion, and restart, although you could equally choose to carry on working until that’s more convenient. Your Mac hasn’t actually restarted, but something logged you out and back in again. If you’re already familiar with kernel panics, this can be most confusing. You’ll then be logged in, and provided this wasn’t the result of a hardware fault, everything should resume as normal. During the black screen phase, the GPU may be restarted, and once it’s up and running it should resume normal function. But instead of your Mac restarting as it would after a panic, you’re then invited to log in. What happens next might set you thinking that it was a kernel panic: the display goes black for a few moments. Worse cases, in which the GPU is involved, aren’t so readily recoverable. In simple WindowServer crashes, the service is restarted after a few seconds, might catch up with some of the backlog of clicks/taps, and carries on. You should still be able to move the pointer about, but all windows are unresponsive, and your Mac is out of your control. Without WindowServer, there can be no GUI, and no handling of clicks/taps.Īs you might then expect, when WindowServer and the GPU crash, everything on your Mac’s display freezes, including the clock. It’s responsible for working out where on the display you have clicked or tapped, thus which window will receive that event to process, and despatches that event to the appropriate app. Part of Core Graphics, WindowServer gathers in images of each of the windows in the system, assembles them into the composite image which will appear on the display, and passes that onto the GPU and display system. The key feature here is WindowServer, a central part of macOS, which is fundamental to its GUI. This article attempts to explain what to look for, and how to respond.

You’re probably familiar with most types of ‘crash’, from uexpected quitting of apps through kernel panics, but would you recognise a WindowServer crash? They range in severity, sometimes just freezing the display for a few seconds, but at their worst can result in unique behaviour – something I experienced for the first time a couple of days ago.

Macos windowserver