macOS Sequoia 15.3 wont let me detect my second display

Ya mon...worked! Connecting a different USB-C hub and both monitors were detected as normal.

Thanks bruh!

Here is my problem and how I fixed it.

The problem:

Monitor connected via hub would not show anything, but I could move my mouse to it and some windows were moved there for sure, so my mac recognized it, but did not show anything. If I connect the same monitor via hdmi directly it worked, so whatever monitor is connected via hub did not work.

Solution:

May not work for everyone.

1. Go to System Settings.
2. Displays
3. If you can see a monitor you are having problem with, click on it and change the color profile several times, eventually it may work again, from there you can change the color profile to the default one. Attaching the screenshot.

P.S.: Not sure if it is a temporary solution or it fixes the problem completely, just fixed it and decided to share. Good luck.

edit: Just checked. When I disconnect and reconnect the monitor the problem is the same, but now I can fix it pretty easily by chaning color profile or refresh rate (apparently does the same thing I guess- refreshes some configs on laptop side).

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.

Re: “My question now is does Apple actually read this support network.”

This is a user to user forum. Apple largely is not here except to moderate it, and is unlikely to see reports of problems unless you contact Apple Support or submit feedback on Apple’s feedback page.

There are other users (not Apple employees) here who can help to troubleshoot causes like trying to use more displays than a given Mac supports. But if you are experiencing problems with a supported configuration, especially ones that seem to be tied to a macOS update, you need to get that information to Apple. Other users here can commiserate, but do not have access to macOS source code, etc. to fix bugs. We are as dependent on Apple as you are.

You may want to include a link to this thread or others that contain detailed problem descriptions when you contact Apple. But they’re not going to notice detailed problem reports here unless you call their attention to them.

@Matias_L

Ya mon...worked! Connected a different USB-C hub and both monitors were detected as normal.

Thanks bruh!

Removing this file fixed it...com.apple.windowserver.displays.plist

Running 15.3.2 here and the nothing has fixed this for me. I have tried all of the suggestions in this thread and none of them work for me. It definitely came with the 15.x releases and I suspect only Apple can actually provide the fix going forward. Just unfortunately has not been in the two updates released to dae.

"Luckily" for me simply power cycling my monitor wakes up this display until the next time it goes to sleep. It continues to be aggravating to say the least.

This is a bad Joke, I am facing the same issue, tried all the suggestions here until now,but none worked. I made it work by switching from the HDMI to a USC-C port, but now I have one less USB port to use for work!

WHEN THIS IS GOING TO BE FIXED?!?!?!?!

Not working for me either.

Deleting the windowsserver.displays.plist file does work for one re-boot, then the next time it sleeps for any amount of time it's the exact same problem again. I have MBP16 and 2 Apple Thunderbolt Monitors. My current work flow is to start the day by disconnecting the Thunderbolt monitors (daisy chained), deleting the plist file, rebooting, reconnecting the Thunderbolt monitors, hope all the USB devices are recognized (usually, but not always), re-arranging the displays to the way I want and make sure the machine does not sleep during the work day. Frustrating...

I ran this setup with NO issues for YEARS until Secquoia.

100% an OS issue.

Deleting the .plist file (and restarting), as mentioned earlier in the thread, seems to work for me. However I don't think it's a permanent fix - the problem can reappear in which case it's necessary to do it again.

I have an M1 mac mini and the second display has been problematic since the start, often failing to be detected. Sometimes there's also an issue with the main monitor going blank - probably somehow related. Previously, putting the Mac to sleep and waking it and/or turning the monitor on/off usually sorted it but these techniques stopped working with Sequoia.

Like others I have a third monitor attached via displaylink.

Fear ye not, oh ye of little faith.

Each case a case, HOWEVER! We all want the shortest path to resolving our very pain:

1. Process Killing/Restarting commands:

sudo pkill -9 WindowServer
sudo pkill -9 usbd
sudo launchctl unload /System/Library/LaunchDaemons/com.apple.windowserver.plist 2>/dev/null; sudo launchctl load /System/Library/LaunchDaemons/com.apple.windowserver.plist

2. System Reset Commands:

sudo nvram -c
sudo pmset -a powernap 0
sudo pmset -a sleep 0

3. Preferense Reset commands:

sudo nvram -c
sudo pmset -a powernap 0
sudo pmset -a sleep 0

4. RESTART YOUR LAPTOP

sudo shutdown -r now

The sleep mode with later systems gave a multitude of users different problems. Do not sleep the Mac. If you leave it for a length of time shut it down as well as overnight.

There are the settings I use but you can change the top two to suit your needs:

Thank you very much your solution worked fine... deleted apple.windowserver.displays....in MacBook air M3 with LG 2k monitor 24qp550.

yes...that fixes it

What worked for me was changing the USB port that my USB hub was connected to + changing the orientation of the cable when plugging in the cable of the USB hub.