Dock won’t switch to open apps on iMac after update to Golden Gate

Since safe mode 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 does not occur in a new user account, that suggests corrupt preference files.

Delete problematic preference files

• In Finder, select Go menu > Go to Folder
• Paste the following into the dialog box then press return

~/Library/Preferences/ 

• Locate and delete the following two files (macOS will create new, clean versions):
  • com.apple.spaces.plist 
  • com.apple.dock.plist
• Restart your Mac

Illowyn wrote:

Low disk space - This computer is running critically low on free hard drive space.

You are using about 500 GB of your 512 GB internal storage. Basically, that's a recipe for grief. That grief can manifest in a variety of seemingly unrelated problems.

The absolute minimum is ~20-25 GB free space, and as a rule of thumb you should aim to have 15-20% of your total internal storage as free space. 

You can try the steps here to safely free up space:

Free up storage space on Mac - Apple Support

Optimize storage space on your Mac - Apple Support

How to free up ‘System Data’ and other st… - Apple Community

Be aware than 1) when you 'delete' data, macOS holds onto it for some period of time (as 'purgeable' data) which can be days in some cases, and there is no way for the user to force that space to actually be freed up; and 2) in my experience, once a system gets that full it can be very difficult to recover. Hopefully you have a Time Machine or other backup (I do see backblaze references, so maybe); if you do not, it may be difficult to create a fresh one at this point.

Consider dumping (i.e., completely uninstalling) NordVPN. Commercial VPNs claim to hide your browsing activity from websites, and while that may be true those VPN providers just sell your browsing data to others. They can also significantly slow your internet speeds. You'd be better off with iCloud Private Relay, though I have no idea how the cost of an iCloud+ subscription compares to NordVPN.

Tashnz wrote:

I'm not sure if you read what I wrote

Yes, I did.

but I have tried ALL the fixes, even something as basic and checking to see if that setting is toggled on or off.

Ok. What are ‘ALL’ the fixes that you tried? Safe Mode? Reinstalling macOS? Erasing your Mac, setting it up from scratch then manually restoring each 3rd party app and utility you had installed, one at a time and testing between each transfer/install?

None of which have made a difference and this issue immediately happened after the update.

The fact that it happened to you, one other person in this thread, and a few people on Reddit proves the opposite of what you think it does. There were over one million beta testers of macOS 27 before launch. The comparatively minuscule number of people with this issue supports the contention that it is NOT a problem with macOS. If it was, why can’t I replicate it?

Incidentally, why do you, “…swipe up to mission control and click an app on the dock,” are you a fan of doing more work that needed or engaging in finger exercises for some reason? It’s only necessary to click an app in the Dock to switch to that app. No three-finger swipe up to enter Mission Control is required. Regardless, whether I’m in Mission Control or not, clicking another app in the Dock switches me immediately to that other app. Just as Apple’s documentation says it should.

If it was only me or a user issue, why are there so many people on Reddit with the same issue, even after trying all of the suggested 'fixes'. We aren't all computer illiterate idiots, sometimes there just is a genuine issue right?

How many…relative to what is now likely tens of millions of users on Golden Gate after its public launch?

I don’t doubt you have a genuine issue. My point is that the issue that you and ‘so many’ other users are experiencing is not intrinsic to macOS 27. Rather, it’s an interaction (= incompatibility) between macOS 27 and some piece of 3rd party software you’ve chosen to install on your systems. Window managers, system monitoring utilities, etc., can cause seemingly unrelated issues. A user who was having problems with Mission Control on Golden Gate determined that TechTool Monitor was the cause…at least one other user confirmed that.

There are certainly bugs in macOS 27, but if they’re intrinsic to macOS then they can be replicated by someone following the same steps as you. Your issue cannot. In another thread, someone went to an Apple Store and saw the same behavior on the Macs there – since Apple doesn’t install crapware on their demo Macs, that was pretty solid evidence that it was a bug.

So…you can assume this is Apple’s fault —despite multiple lines of evidence to the contrary— and hope Apple fixes it. IMO, hope is not a plan. You might get lucky and the developer of the problematic extension/app will push an update that makes it compatible with Golden Gate. In some cases, that update might have happened already, which is why it’s important to keep all your apps and utilities up to date (and if updates have stopped, find a replacement).

It's fixed!!! I just updated to MacOS 27.2 and it's working like normal again. Also the glitches with split screens etc seem to be resolved.

Are you serious lol. If you just google 'Mission Control issues MacOS27' there are pages and pages of different reports, social media posts, videos, screen recordings, and articles about how buggy it is and how many people are having various issues with mission control and dock not working, black screens, windows freezing in mission control. If it was something about my specific settings, or third party apps then the issue would resolve in safe mode. And it doesn't. I was on support chat with Apple for 30 minutes and they couldn't resolve the issue even after reinstalling the OS. It's literally a known issue with a lot of people.

Why are you getting so defensive as if you created MacOS yourself and we are attacking you. It's super weird lol, like your ego is getting bruised for some reason.

Also I've tested the 'new user' account and it didn't work. And I have 100GB of space, so it's not a storage issue, it's a iOS issue, because it immediately became a problem after the update.

Thanks! I created a new user as recommended and the problem existed in the new profile, as well. I've also noticed that, when I'm on the desktop, I can navigate using the dock; the problem only occurs when I'm in an app window and try to switch to a different one. My Etrecheck report is below.

This is driving me CRAZY. I have a lot of things open for work and Uni, and now when I swipe up to mission control and click an app on the dock, I'm just taken back to where I was last rather than where I wanted to actually go. It ends up with a lot of extra swiping and clicking just to get there. I just did the update hoping for a fix... but nope.

Super disappointing and frustrating. I've tried all of the 'fixes' I could find out there, and it's still a problem.

It’s helpful to know that you’re having this issue with a ton of storage space. I had to clear space on my drive just to do the update, so the storage issue was plausible—the update was so big it caused the error—but if you’re still having the problem with 100GB free, then it’s got to be something else causing the dock to malfunction.

Tashnz wrote:

Also I've tested the 'new user' account and it didn't work. And I have 100GB of space, so it's not a storage issue, it's a iOS issue, because it immediately became a problem after the update.

If it was just a macOS issue, it would affect most/all users. I can click on an any app in the Dock, and that app becomes active. There is a setting in System Settings Desktop & Dock that controls whether or not you switch to another Space when you click on an app in the Dock, if that app has an open window in another Space:

However, that setting only affects the active Space, not the app becoming active. I'm in Safari now, and I have a Word document open in another Space. With that setting off, if I click on Word in the Dock, then Word becomes the active app in this Space.

The bottom line is that this is not an issue with macOS, but rather with your specific systems.

I'm not sure if you read what I wrote, but I have tried ALL the fixes, even something as basic and checking to see if that setting is toggled on or off. None of which have made a difference and this issue immediately happened after the update.

If it was only me or a user issue, why are there so many people on Reddit with the same issue, even after trying all of the suggested 'fixes'. We aren't all computer illiterate idiots, sometimes there just is a genuine issue right?

I've been chatting to people on Reddit with the same issue. All hoping that the bug fix update would have helped, but it hasn't. I understand there are different ways to get access to a recent app (command - tab for example), but I am SOOO used to doing things this way, it's how I have been doing it for years now, that it's just muscle memory and I have so many things open both on my MacBook Air and my iMac that doing it differently slows everything down. And, this is actually something that 'should' work, I shouldn't need to do things differently, it should just work as advertised...

Tashnz wrote:

Are you serious lol. If you just google 'Mission Control issues MacOS27' there are pages and pages of different reports, social media posts, videos, screen recordings, and articles about how buggy it is and how many people are having various issues with mission control and dock not working, black screens, windows freezing in mission control.

Yes, there are bugs in macOS 27, including some with certain functions of Mission Control. There have also been conflicts with incompatible 3rd party extensions affecting Mission Control. The difference is that the former can be reproduced by anyone following the steps described to see the bug. The latter cannot, they affect specific users...usually a small number of them.

If it was something about my specific settings, or third party apps then the issue would resolve in safe mode. And it doesn't.

Not necessarily. It could be corrupt system files. It could be a bug, triggered by a very uncommon combination of settings.

It's literally a known issue with a lot of people.

"A lot of people," is a uselessly vague term. If there are ten thousand people with this problem (and I would bet that's a vast overestimate), that's less than 0.1% of users running Golden Gate. Less than 1 in 1,000 users.

Why are you getting so defensive as if you created MacOS yourself and we are attacking you. It's super weird lol, like your ego is getting bruised for some reason.

I prefer to deal in facts. If a bug affects a minuscule, essentially insignificant fraction of users, then very unlikely to be an OS-level bug. It's more likely a compatibility issue/conflict or a specific problem with corrupted system files. However, you seem terribly reluctant to even consider that the problem might have something to do with decisions that you made about installing software/extensions.

As I said, personally this is a non-issue for me. I click on an app in the Dock, and if that app was already running then the app I click becomes active immediately (and if the app wasn't running, clicking it launches it). It works that way when using an app, it works that way in Mission Control. That's how it's worked since the Dock was introduced with macOS X (and how it was with Launcher, that I used on System 7 on my Macintosh SE, somewhere north of three decades ago). Click a running app, that app becomes the active one.

Regardless, good luck with your issue(s).

Just updating to say that I decided to see what would happen if I installed Golden Gate on my MacBook Air (M4), which has over 300GB available disk space, and I'm having the exact same problem. That suggests an incompatibility with something I have running on both machines as the most likely culprit, I think?

Hooray! Just updated and it's all working fine again! So glad it's fixed!