CMD-Tab not working

clp698 Said:

"I booted in Safe Mode and the problem still persists. I then logged out and restarted as a guest user and CMD-Tab worked as expected. So I guess there is something in my user account that is keeping the function from working. Thank you for all for taking the time to help in with this problem."

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1. Create a New Administrator:

If if there is no issue in this newly-created guest user, then now create an administrator. It is most likely an issue with your current user.

Then...

2. Delete this Current User:

Once created, log into it. Be sure to transfer data (i.e. images and documents to this new administrator. From there delete this administrator you are logged into. You should be set from there.

clp698 wrote:

I use Cmd-Tab a lot to switch Applications. However, on my MacBook Pro, running macOS Catalina, it does not work. When I use it, the running Apps are shown but when I choose one that is running in a different space, it doesn't switch to the App in that space. If the App that choose is in the same space that I am in then it switches to correct App. This command works OK on my 27" iMac. I have set all of the MBP system preferences to be the same as the iMac system preferences, but still have the problem. Very frustrating.

Seems a glitch in the UI—

I would try simply reinstalling the Combo update macOS 10.15.4 https://support.apple.com/kb/DL2037?locale=en_US

on top of your existing macOS 10.15.4

clp698 Said:

"CMD-Tab not working: [...]This command works OK on my 27" iMac. I have set all of the MBP system preferences to be the same as the iMac system preferences, but still have the problem. Very frustrating."

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Reset the SMC and NVRAM:

Sometimes operations are performed and then the keyboard settings become manipulated, technically (in this case, the keyboard). So... Try resetting the SMC and NVRAM. Then reboot, logging in once more.

You probably only need to do one small thing: go to System Preferences->Mission Control and CHECK this box:

It could be a corrupted preference file.

You could try unchecking that box, quitting system preferences and then checking it again to see it gets "unstuck".

If not, try deleting the corresponding preference file: in the Finder, press command-shift-G and type or paste

~/Library/Preferences/com.apple.spaces.plist

Drag that file out of the folder and place it on the Desktop for now (just in case you may want to put it back later).

Logout and back in.

Go to System Preferences->Mission Control and set things as desired. See if they now work.

clp698 Said:

“Humm, I will have to think about that. Sounds scary.”

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Important:

Well, if you don’t know what you are doing, then don’t perform it.

Backup Your Mac:

To prevent data loss, be sure to Back up your Mac with Time Machine, prior perform to the user-switch.

clp698 Said:

”CMD-Tab not working: I use Cmd-Tab a lot to switch Applications. However, on my MacBook Pro, running macOS Catalina, it does not work. [...]I do Time Machine Backups regularly. Thank you for your help with this matter.”

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Reinstall the macOS Anew:

If nothing mentioned before this reply works, then reinstall the MacOS anew. All would be deleted; you would reinstall the macOS; then you would reinstall the software either by containing the developer or by use of Migration Assistant(see below)

Perform the following in the order provided:

I. If it applies: Back up your Mac with Time Machine - Apple Support

Then...

II. Reinstall the macOS Anew:

1. Boot: into Recovery Mode.
2. Open: Disk Utilities
3. Delete: the partition
4. Reinstall: the macOS

Once Installed Anew...

III. Reinstall All the Software:

1. Use Migration Assistant to move Apps a Files back in.
2. Ask developers for new software keys- but contact the developers only --- none other --- elsewise you might end up with malware and spyware installed.

Does the problem still occur:

a) In a different user account?

b) In your account, when booted in Safe Mode?