Dual Monitor Setup crashing Monterey

Consider downloading this little "discovery" utility, Etrecheck. It changes nothing. but it can produce an anonymized report that can be posted back on the forums.

Change its preferences to "allow full disk Access" before you say "GO".

Using EtreCheck to Troubleshoot Potential… - Apple Community

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MacOS did make some changes in the area of power management for multiple displays for Monterey.

What is the setting of Low power Vs High power when this happens?

If you change that setting, does the problem change in any way?

Use High Power Mode on your 16-inch MacBook Pro with M1 Max - Apple Support

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Thank you so much for this... After spending an unfortunate amount of time attempting to TSHOOT this ridiculous issue, I came across your post/solution.

After a simple OS upgrade to Monterey, Apple support and your company's tech support recommends purchasing new cables to solve the issue?! When the issue didn't occur whatsoever on BigSur? That's completely senseless.

What's interesting is that I'm not using my internal panel in my setup, but setting the internal panel to 50 Hertz resolved the issue!

If this helps anyone, I'm currently using 3 external monitors with my laptop closed. The 3 external monitors are:

1. 1440p @ 60hz
2. 4k @ 60hz
3. 4k @ 60hz

Never had an issue till downgrading to Monterey.

I've had a very similar issue to this, that immediately started on upgrading to Monterey. LG 4K UHD 27UN83A – worked perfectly via USB-C, then crashed WindowServer straight after the update.

Symptoms were returning to the login screen and asking for password over and over in an endless loop. Only unplugging the cable stopped it. HDMI + adapter was fine, as was the original USB-C in Safe Mode.

The fix I found...

• Deleted com.apple.windowserver.plist from the Preferences / ByHost folder
• Went into Safe Mode and checked the monitor worked. Returned scaling to default, and set Frame Rate to 30.
• ON THE LG MONITOR, changed DisplayPort Version from 1.4 to 1.2 in General Settings.

The first two I had tried before, so it's likely the monitor setting was the crucial element. Afterwards I rebooted and everything worked as it did on Big Sur, and was able to change scaling and frame rate back.

Hopefully this helps someone else.

I have a 2019 MBP with 64GB and have never seen the beach ball of death or complete freezes before Monterey. As mentioned, the problem appears at EVERY Zoom Desktop or Google Meet call in the browser and also YouTube videos. It gets worse with two external monitors attached but happens less often with the MacBook solo.

It also sometimes freezes when typing in forms, just like I'm doing now and uploading files in Slack, but not that often as in the video calls.

I will wait a few weeks before going back to Big Sur because it's been a hassle since I'm fully remote now.

adapters only, no Docks?

Kernel Panic Reports are stored at:

/Library/Logs/DiagnosticReports

If you copy and paste that string into:

Finder > Go menu > Go to Folder

it will take you to where those reports are stored.

They are named with Date&Time and start or end in ‘panic’

If you find one, please post the entire report here, by using the “additional text” Icon in the reply footer (looks like a paper with writing).

Please don’t post more about 20 lines of any other types of reports — they are interminable, and any information useful for this purpose is on the first screenful.

There are three quick take-aways from any panic report.

1) The panic-reason,

2) the extensions present at the "scene of the crime", and

3) the BSD process in which the problem occurred.

One more item that is important is the names of any third-party Extensions you have added. They are shown FIRST in the extensions loaded section

I am having exactly the same issue as givindb. Have tried removing all display apps like Magnet etc and ensuring that nothing set to start at login. But when connected to dual monitors macbook pro 16" crashes on wakeup . When not connected to monitors no issue.

<< Yes, I disabled automatic graphic switching but it didn't help. >>

'automatic graphics switching' has NOTHING to do with this issue. Automatic graphic switching is not used when an external display is connected -- by Hardware design, ONLY the Discrete graphics processor is used when servicing external displays.

What I posted has to do with new Monterey feature: low-power/high-power mode.

I have a similar situation.

My Intel-Based MBP 16" 2019 has two SMK Link USB-C hubs https://www.smklink.com/products/usb-c-multi-port-hub, used to connect to 2 Samsung u32H85x 4K monitors via HDMI.

It worked great for a year through previous two OS releases, but is doing exactly what govindb describes, but only after initial unlock, then screen timeout due to idle timeout, and then resume.

I tracked it down to one specific monitor. Machine works great with internal screen, internal screen+monitor1 but dies whenever it is in internal screen+monitor1+monitor2 or internal screen+monitor2

I have done a thermal sensor reset and nvram reset and just did a full OS reinstall, the issue persists.

That's the thing, I wish I knew!

The monitors are identical.

Bought at the same time. SNs are at most few numbers off.

Firmware on them the same.

I am using them in the native 4K rez and with same zoom factor (~200%? I think). I am running them at 60hz, their max rate

The monitors are connected by https://www.monoprice.com/product?p_id=2529 at 15' length, bought at the same time.

I went a bit long on the cables since they have to go from the machine under the desk through one hole then up and over through another two holes for each monitor. I probably could have gotten away with 10' but oh well.

The only thing I haven't tried is swapping the cables between the monitors, due to aforementioned pain in the behind with routing them under my desk. I could be persuaded to do it through

I want to stress that this all worked from day one of this machine on this corporate macbook using the OS that was one before Big Sur, then on Big Sur, and is now reliably broken. Seems honestly like a driver issue.

Happy to provide dumps, even remote debugging. What I don't want to do is invest into different cables which is what my IT suggests, stretching out there.

Those are the correct certified cables, and monoprice generally makes good stuff, but anything could fail.

You could swap just the computer ends and not have to re-pull. that would tell you if the issue followed cable+display.

I did that already, swapping out the cables between the docking stations, and then also swapping docking stations on the right-side ports.

Actually, I think I have to correct myself on this:

I tracked it down to one specific monitor. Machine works great with internal screen, internal screen+monitor1 but dies whenever it is in internal screen+monitor1+monitor2 or internal screen+monitor2

I am re-testing again and it seems like internal screen+monitor1 works and internal screen+monitor2 works, so only internal screen+monitor1+monitor2 does not (like the OP in this thread). The test cycle is 10 minutes long due to group policy mandated screen timeout...

Yes, retesting confirms. Any single monitor using either dock using either cable == ok. Both external monitors no matter which cable and dock combo == kaput.

This kinda wrecks the workplace situation here with these fancy shiny monitors.

How can I get you the right things (memory dumps, profiler traces, whatever) to fix it?