MacOS 27: "WindowManager is capturing your screen"

The “WindowManager is capturing your screen” notification appears to be associated with Mission Control or Spaces on your Mac. 

You have reproduced the behaviour when using Mission Control or switching applications, and, importantly, it stops when Displays have separate Spaces is disabled.

Other macOS 27 users have reported the same notification when switching Spaces or using Mission Control, including a report involving a 14-inch M1 MacBook Pro with two 4K external displays. 

There are also reports that the behaviour was not present in macOS 26. These reports are useful supporting evidence, but they do not establish the cause.

Apple documents Displays have separate Spaces as the setting that allows each display to have its own Spaces. Apple — Use multiple spaces on Mac

For now, the simplest workaround is to turn off Displays have separate Spaces under System Settings >> Desktop & Dock >> Mission Control. 

The disadvantage is that your displays will no longer have independent Spaces.

If you want to keep the setting enabled, I recommend reporting the behaviour to Apple through macOS Product Feedback.

Include your Mac model, macOS 27 version, two 4K displays connected through a Thunderbolt dock without DisplayLink, the circumstances that trigger the notification, and the fact that disabling Displays have separate Spaces appears to prevent it.

Based on the available information, it is reasonable to regard this as a possible macOS 27 regression involving Mission Control/Spaces and multiple displays, rather than assuming that the Thunderbolt dock or displays are responsible.

The specific cause has not been established.

We can understand the frustration, especially if 27.0.1 has not changed the behaviour and you are seeing the same symptoms described in the other thread.

At this point, though, if the issue is a macOS regression, it really is something Apple needs to address.

You have already submitted feedback and confirmed that the problem persists after the latest update, so there may not be much more that can be done from the user side other than continuing to provide Apple with specific examples and diagnostics if requested.

Hopefully the reports from multiple users will give Apple enough information to identify and fix the underlying issue in a future macOS update.

1ixi1 wrote:

Most frustrating that "Displays have separate Spaces" is required for yabai. So the "workaround" won't do for yabai users. And everything worked just fine before updating to 27. Thanks Apple.

I think that this is just a minor annoyance, and does not impact the use of the mac.

I have not been able to reproduce this, however.

Here are two things that you may want to try:

1) Turn off Stage Manager. A few posts I have seen appear to suggest that using Stage Manager may have an impact on this

2) Check if the external display is using AirPlay and not a directly attached display. AirPlay does work differently, and perhaps (as my external display is used directly) that is why I do not see that message. I may try using an iPad with AirPlay and see if it triggers that message or not.

Updated to 27.0.1 and still the same issue. I already used macOS Product Feedback.

It is highly related to this one: macOS 27 Mission Control freezes for ~1 s… - Apple Community

I have the same symptoms. It is really bad, and really disappointing. Apple has the hands on its own hardware and software. There is no excuse for such regression.

Seriously, it is absolutely NOT a minor annoyance. I constantly switch from a work space to another and every time, I have this icon and it slows down MacOS all the time compared to before.

Stage manager is turned off and my two external displays are connected through a thunderbolt dock (without display link or any other software layer). But I'm just repeating what I said in my first message.

In the meantime, I was fed up with this and switched back to cachyOS on my framework desktop which is now 100 times more responsive.

I really hope Apple fixes this.

Also have this icon saying "Windows manager is capturing your screen" is not reassuring at all even though in this case, it is clear it is from Mission control...

I could renew my Mac as well, but I never do it before it stops to accept the new major version of the OS (So renewal will probably be in 1 year or 2). Will see by then...

Tried the proposed workaround but the issue persists.

Most frustrating that "Displays have separate Spaces" is required for yabai. So the "workaround" won't do for yabai users. And everything worked just fine before updating to 27. Thanks Apple.

Still not fixed, MacOS 27.2 (26B123), 14 inch M1 Pro MacBook Pro