macOS 27: Multi-monitor screen black after moving Full-Screen Space

Question

Level 1

23 points

macOS 27: Multi-monitor screen black after moving Full-Screen Space

Hi everyone,

I am experiencing a highly specific UI rendering bug on a triple-display setup (built-in Mac screen + 2 external monitors) running the new macOS 27 Golden Gate MBP M5.

The Exact Trigger:

The bug only occurs when I open Mission Control (F3) and drag a Full-Screen application Space from one monitor to another display.

The Symptoms:

As soon as the full-screen space is moved to the target monitor, the screen where it originally came from instantly turns completely black.

All desktop icons and the wallpaper disappear on that specific screen.
However, the Dock at the bottom and the Menu Bar at the top remain fully visible and active. I can click on apps but nothing will open.
If I open Mission Control, the desktop thumbnail at the very top correctly shows my wallpaper and layout on opened apps. But as soon as I exit Mission Control, the main workspace remains pitch black.

Current Workaround:

Running killall Dock in the Terminal temporarily forces the UI to reload, restoring the wallpaper and workspace. But doing this every time I move a full-screen window across my three monitors is extremely disruptive and not a permanent solution.

It seems like the new window server / rendering engine in macOS 27 fails to properly re-initialize or clear the dedicated Space on the original monitor after the full-screen window is moved via Mission Control, leaving a dead "orphaned" black Space behind.

Has anyone found a permanent fix for this multi-monitor Full-Screen Space bug in macOS 27?

Thanks for your help!

MacBook Pro 14″, macOS 27.0

Posted on Sep 21, 2026 3:31 AM

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Answer 1

Oct 22, 2026 4:37 AM in response to Patrick995

Fixed in macOS 27.2 RC

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Answer 2

Sep 21, 2026 5:46 AM in response to Patrick995

There have been many issues reported with Mission Control on macOS 27 Golden Gate. Some have been resolved by identifying and removing incompatible 3rd party extensions, others are bona fide bugs.

Have you rebooted your Mac? If not, that's the first step. If that does not help, then see if the problem is present when you boot in safe mode. That process performs some system cleanup and clears caches, and also disables 3rd party extensions that may cause problems.

Start up your Mac in safe mode - Apple Support

If that does not correct the issue, test in a new user account. A newly-created user account will have all settings at default, and if the issue does not occur in that new account then it provides guidance on what may need to be changed to correct the issue.

Add a user or group on Mac - Apple Support

Once the testing is complete, the new account can easily be deleted.

Delete a user or group on Mac – Apple Support

Those steps will help to isolate the problem.

It might help to download and run EtreCheck, written by a long-time forum member. The free version is fine. Post the full report using the Additional Text button. No personal information is revealed.

If the issue persists in safe mode and a new user account, that suggest that it's a bug that Apple needs to address. Bugs can be reported to Apple here:

Feedback - macOS - Apple

Reporting issues like this to Apple is the only way to get them fixed. They do prioritize bugs based on frequency of reports, so the more people who report it, the faster it will be addressed.

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Answer 3

Oct 4, 2026 7:43 PM in response to Patrick995

I can add a little more detail. My workaround is to add an extra desktop space to each monitor, even if I'm not using it. The blank screen problem still occurs, but I can click to the superfluous space, then go the the space I need to use. That seems to kill the orphaned space.

I'm not suggesting I like this in any way, just noting that it get's around the blank screen, which, otherwise, is difficult to kill.

-Darren

Setup used:

MacBook Pro M4 Max

Three Apple Thunderbolt Displays, using two Apple TB3 to TB2 dongles

(I have not yet tested this with just the internal display and no external monitors. Will update when I have some experience to share.)

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Answer 4

Sep 24, 2026 10:52 PM in response to neuroanatomist

Same problem here. I get it temporarily resolved by bringing another full screen app and then switch to desktop. The black screen only happen in the "Desktop" in multi screen (I have 3 screens at the same time)

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Answer 5

lorcya

Level 1

32 points

Oct 20, 2026 12:34 PM in response to Patrick995

A mi igual , lo unico que me queda visible es el Dog, con la consiguiente molestia de que para revisar 50 documentos me tengo que pasar varias horas para que las ventanas no queden maximizadas y pueda seguir

trabajando.

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Answer 6

Patrick995 Author

Level 1

23 points

Sep 24, 2026 11:00 PM in response to alexisscout

Yes true! Sometimes when I try to bring another full screen app to the blacked out space, the other screen where I drag the app from turns black instead then…

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Answer 7

jbbod

Level 1

0 points

Sep 27, 2026 3:08 AM in response to Patrick995

While I was watching full screen a video and I wanted to switch back to normal view, and the screen went black. I had a space to be able to go back to my screen...

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