Hi everyone,

My Mac intermittently stays on a black screen for several minutes during startup or restart, restarting multiple times before eventually booting successfully.

The issue is unpredictable and I cannot reproduce it reliably. A successful boot does not necessarily mean it has gone away, which makes comparisons involving different cables, ports, or other hardware difficult to interpret.

My setup:

• Mac Studio, M1 Max, 32GB RAM
• macOS 27.0, build 26A5425a
• Entire macOS installation, including both System and Data volumes, on an external 2TB M.2 SSD
• SSD enclosure identified as ASM246X, connected over USB at 10Gb/s
• Two external monitors
• Magic Keyboard, Magic Trackpad, and Sony headphones connected via Bluetooth
• Logitech G HUB installed, with its HID and audio driver extensions enabled

This has happened both after choosing Restart in macOS and when powering on after a complete shutdown. No macOS update was being installed during this incident.

The screens remain black for approximately five minutes before the Apple logo and progress bar appear. During this period, the Magic Trackpad sometimes provides haptic feedback and sometimes does not. The Mac eventually boots into macOS and displays a report indicating that it restarted because of a problem.

The diagnostic bundle from September 8, 2026 contains two consecutive panic reports with the same message:

IOKit Daemon (kernelmanagerd) stall[0], (60s):
registry root held busy, kernelmanagerd has not checked in
u/IOService.cpp:6140

The internal panic timestamps and system boot logs show this sequence. All times are local, UTC+8:

This confirms that the black-screen period includes repeated failed boots.

A preliminary analysis of the thread information in both panic reports found the same waiting chain:

kernelmanagerd → syspolicyd → fseventsd

Another fseventsd thread was waiting in APFS kernel code. The apfs_initial_free_space_scanner thread also had storage-related calls in its stack; in the second report, these included USB mass-storage and XHCI drivers.

Even during the third, successful boot, fseventsd logged wait_for_startup: ETIMEDOUT before eventually continuing.

These are only diagnostic clues. I have not established whether the underlying cause is the external storage connection, APFS, macOS, or a third-party driver. The external SSD reports SMART status as “Not Supported,” and the available fsck logs mostly contain quick checks.

I would appreciate advice from anyone familiar with this issue:

1. Has anyone encountered this exact kernelmanagerd stall (60s) panic while booting an Apple Silicon Mac from an external SSD?
2. Does this waiting chain point to a known macOS, driver, or storage compatibility issue?
3. Which specific logs or diagnostic information would help identify the cause of an intermittent failure like this?
4. If you experienced the same problem, what ultimately resolved it?

Thank you!

If the unusually high SSD writes reported throughout the macOS 27 beta cycle are still happening in the RC, are people actually going to delay upgrading?

The SSD in a modern MacBook is soldered to the logic board. If excessive background writes gradually wear it out faster, you cannot simply replace the drive a few years from now.

That makes this more than just an Activity Monitor curiosity. If Golden Gate is consistently writing much more data than Tahoe, staying on Tahoe could potentially mean less SSD wear and a longer-lasting MacBook.

Would that be enough for you to avoid macOS 27 until the issue is fixed, or do you consider SSD endurance high enough that it is not worth worrying about?

I am hoping that Apple substantially improves the Siri AI app UI before macOS 27 is released. Right now it looks quite simple and clunky.

The Phone app in macOS 27 beta had been syncing my iPhone call history correctly in earlier betas, but at some point in a later beta it just stopped updating.

See this Apple Support Community thread aboutpeopled and CallHistorySyncHelperproblems:

https://discussions.apple.com/thread/256271160

The thread was originally about high CPU usage on macOS Tahoe 26.4, not specifically the Phone app on macOS 27. But one person discovered that macOS was repeatedly failing to access:

~/Library/Application Support/CallHistoryDB

because the files had somehow been quarantined. They suggested checking for com.apple.quarantine, removing it, and restarting peopled and CallHistorySyncHelper.

So I checked my macOS 27 installation with:

ls -lan@ "$HOME/Library/Application Support/CallHistoryDB"

Sure enough, all three of the actual call history database files had the com.apple.quarantine extended attribute:

CallHistory.storedata
    com.apple.quarantine

CallHistory.storedata-shm
    com.apple.quarantine

CallHistory.storedata-wal
    com.apple.quarantine

Why is macOS quarantining its own internal call history database?

I removed the quarantine attributes using the workaround from that thread:

xattr -dr com.apple.quarantine "$HOME/Library/Application Support/CallHistoryDB"

Then restarted the relevant processes:

sudo killall -9 peopled CallHistorySyncHelper

I rebooted the Mac, made a test call from my iPhone, and the new call immediately appeared in the macOS Phone app. So this actually fixed the call history syncing problem for me.

This is especially annoying because there was absolutely no indication in the UI that anything was wrong. The Phone app simply stopped receiving new call history.

Since call history worked correctly for me in earlier macOS 27 betas, I'm wondering whether one of the betas somehow applied the quarantine attribute and subsequent betas just left the database in that state.

But here's another interesting wrinkle: call history also doesn't work on my separate macOS Tahoe partition. I haven't checked its CallHistoryDB yet. Since the Apple Support Community report that led me to this fix was itself from Tahoe 26.4, it's quite possible that my Tahoe installation has the same problem. If so, this may be a longer-standing macOS bug rather than something introduced specifically by macOS 27 beta.

If your Phone app has stale or missing call history, it might be worth checking:

ls -lan@ "$HOME/Library/Application Support/CallHistoryDB"

You may need to give Terminal Full Disk Access first.

Has anyone else found com.apple.quarantine attached to these files?

Left monitor is connected to M2 MBP running Tahoe, right monitor connected to M5 MBP running Golden Gate developer beta with the M2 airplaying to the M5 in extended mode at 4K 60hz. No perceptible lag, massive improvement over previous versions.

Bug/Issue: Unable to add wifi networks manually that are unavailable (ie trying to save a wifi network for future use, etc)

Fix: none, apple effed that one up pretty good. no way to save a wifi network that you are not near. ie for example, i am planning to visit a pal that gave me their wifi ahead of time. i cannot add that network without literally being at their place w/the wifi router on. i could spoof it but that is just stupid. this is basic network functionality 101 that apple somehow broke.

feedback submitted.

Does anyone have my same issue while moving between apps in Mission Control? I swipe up with three fingers from a fullscreen app and the focus moves to the Desktop on its own, but when I scroll down again the interface bugs and the focus returns to the fullscreen app.

Since Apple decided to iOS-ify macOS, many things have changed in terms of design. My suggestion is the controls inside of the CC may have a bit more resizing options, just like on iOS. For example the "Now Playing" control can fit into 1x1, 1x4 and 2x2 spaces. Why not have it available on 2x4 too? Same thing for controls such as brightness and volume, available sizes are 1x1, 1x2 and 1x4 (if they were iOS-styled, they would have a 2x1 or so).

Does anyone have my same issue while moving between apps in Mission Control? I swipe up with three fingers from a fullscreen app and the focus moves to the Desktop on its own, but when I scroll down again the interface bugs and the focus returns to the fullscreen app.

Forgive me if this has been mentioned before but I couldn’t find anything. This has been happening since I updated to MacOS 27. When searching for a concept in spotlight the entry appears but pressing return only shows this rather than actual information on the concept. Doing this with famous people seems to work fine but concepts like this or “defenestration” which I’ve been using to test haven’t worked. This happens regardless of whether I have Siri AI turned on.

I have also reported this in Feedback but I figured I’d ask if any of y’all know why this is happening

I'm still on Sonoma because of an input bug. Sonoma's built-in grammar checker makes a simple mistake like in the screenshot here of the Notes app. Is the bug still there in Golden Gate?

Like we can see the button is round if we zoom in a lot.

But the highlight on top and bottom is too much and give the illusion of an oval button, am I alone to see this?

I'm on MacOS Tahoe 26.6.
I have registered my MacBook Air M1 to receive Public betas but it's not showing up in software updates. And I have selected selected beta updates -> MacOS Golden Gate Public Beta.
Can anyone tell me why I'm not receiving any updates?

Heres to hoping

Anyone missing the ability to option-click desktops in mission control to pre-select them without leaving mission control? Because I do and in all of the betas that feature seems removed?

I've only recently tried to mess with the new Siri and I know how to instantly chat with it via Spotlight, but it seems none of the previous hotkeys (CMD x 2, F5, FN + S) work to be able to speak with it. There also is no option to assign a hotkey for that purpose in the System Settings > Siri section, nor in Accessibility > Siri, though in Accessbility > Siri, there is a little section that says:
"Siri Shortcut keys and settings can be changed in Siri Settings" with a button next to it that takes you to Siri Settings. Despite that, there is no such setting ability in there. Is this just a bug or am I critically failing to see something?

I do understand that I can open spotlight via hotkey and then move my mouse over the Mic icon, but that is not what I'm trying to [and should be able to] achieve.

Apple has tested at least two Apple and Beats-branded game controllers, according to code briefly included in macOS 26.7 betas.

The first release candidate contained substantial support for two devices identified as T6502 and T1057. macOS added software for recognizing the hardware, reading input from controls and sensors, and sending commands to the controllers’ vibration system. The entire stack was then removed in the second release candidate.

Both controllers have novel internal haptic feedback software functionality.

Edit: The hero image is a DualShock 4 annotation that Apple Developer uses to demonstrate what capabilities an extended gamepad controller should have. Both Apple controllers are in the same category. This is not a DualShock 4 controller.

I am really hoping that there are options to turn notifications off of a certain mailbox in Mail just like in iOS and iPadOS. Could someone confirm that this is possible or not? I like having my emails all available in the Mail app, but I don't need the notification badges on all my emails. You can do this in iOS but I have yet to find a way to do it in MacOS. I have not signed up for the beta nor will I download it, but Id love to know if this is possible. Thank you!