Can anyone help??
I've just moved to macOS Sequoia 15.3
Now my second display (thunderbolt) which worked perfectly, about 2 hours ago is now dead and cant be detected. I've looked on line and it turns out it's a common problem. I wish I had just left the upgradfe.
IS there a fix?
Thank you
iMac 27″, macOS 15.3
This has nothing to do with the displays, monitors,... in my opinion. I have been using the same setup with my old MacBook Pro and new MacBook Pro for about 5 years. Two external monitors - one display port / one HDMI. I have NEVER had an issue with the external displays coming online until upgrading to 15.3. It is always the HDMI display that does not come back after the system sleeps.
I have found that power cycling either the monitor (easier of course) or the laptop will bring all three back online and they will all remain fully functional until the next time it sleeps.
User level:
Level 1
32 points
Feb 13, 2025 4:44 AM in response to WozaMAC
First, I ran this command:
sudo find / -name "*windowserver*" 2>/dev/null | tee ~/Desktop/windowserver_files.txt
Then I analyzed wherever the plist files are there.
Then this
sudo rm -rf /Library/Preferences/com.apple.windowserver.*
Then I rebooted. It worked for me. I upgraded to 15.3.1 hoping it would fix the issue but it did not.
UPDATE: This fixed my problem!!!
RonKabele wrote:
I believe that is the case for the M1 Mac Mini, perhaps one of the laptops. The Mac Studio M1 I have supports three monitors because that’s what I’ve been doing for over two years. But I do have a Kensington TB3 dock where two of my monitors are plugged into. I would also guess the first M1 Mac Pros support at least three or more monitors.
The M1 Mac mini supports two monitors - one connected via USB-C or Thunderbolt, one connected via HDMI.
The M1 Max and M1 Ultra Mac Studios support up to five monitors.
There were no M1-series Mac Pro desktops.
With regards to MacBook Pro notebooks,
not working for me :(
This does not work for everybody. Even if it did, it *clearly* indicates some kind of OS issue.
Thanks @sgreadly
It works for me!
I've tried all of these things suggested below 10 times and nothing is working for me! Please fix it asap
I did this but it doesn't seem to fix the issue, does anyone know an alternative fix?
You are literally a life saver, I can't thank you enough
This fixed my issue finally. Thank you!!!
This is god send! This one worked out for me and I've been having the issue for a week! Thank you so much.
Re: “To Apple, when will the second external monitor issue be fixed?”
This is a user-to-user forum. Apple largely is not here except to moderate it, and so will not see or reply to your message.
Removing this file fixed it...com.apple.windowserver.displays.plist
I think this is the best solution, this worked for me thanks
I was on with Apple support and we followed this process, and it did not work. Updated to 15.3.2 when it stopped working.
macOS Sequoia 15.3 wont let me detect my second display
