Dell D6000 - no monitors detected macOS Tahoe 26.3.1 & DisplayLink Manager 15.1

[automised_matt]

DisplayLink Manager 15.1 fails to detect any monitors on macOS Tahoe 26.3.1. The dock is fully functional at the USB level (peripherals work, device appears in system_profiler USB tree) but no virtual framebuffers are created.

Setup:
- macOS 26.3.1 (25D771280a)
- MacBook Pro 16" M1 Pro
- DisplayLink Manager 15.1
- Dell D6000 (DL-6950)
- FileVault enabled
- Monitors worked immediately prior to the 26.3.1 update

Diagnostics:
- system_profiler SPDisplaysDataType shows built-in display only
- ioreg confirms DisplayLinkUserAgent has claimed USB interfaces
- TCC logs confirm Screen Recording permission is granted (authValue=1)
- BetterDisplay also does not detect external displays
- Full uninstall/reinstall, tccutil reset, plist deletion, dock power cycles - none resolve it

Root cause appears to be this error in the DisplayLinkUserAgent process log:

Couldn't read values in CFPrefsPlistSource (Domain: 73YQY62QM3.com.displaylink.DisplayLinkShared, User: kCFPreferencesAnyUser, ByHost: Yes, Container: (null), Contents Need Refresh: Yes): Using kCFPreferencesAnyUser with a container is only allowed for System Containers, detaching from cfprefsd

The shared preferences domain 73YQY62QM3.com.displaylink.DisplayLinkShared does not exist on disk. It looks like Tahoe 26.3 tightened enforcement of container rules for kCFPreferencesAnyUser, preventing DL Manager from reading or creating its shared preferences.

Anyone else seeing this on 26.3? Have filed a support ticket as well.

[pvm]

Experiencing the same issue with an identical setup except for MacBook Air M4.

[Jody G]

Same Issue but haven't done that much digging into it. I am running the same OS as the original poster.

[Szymon]

Hi automised_matt,

I had a quick check of your logs. What is wrong - there are no signs of monitor presence connected to the dock. Does any of the monitors appear when you unplug and plug monitor DP cable or power cycle the monitor?

BTW thanks for the pointers, however "Couldn't read values in CFPrefsPlistSource..." is not an indication of something going wrong here :)

One thing to note: with FileVault enabled you won't be able to use DisplayLink displays on the login screen anyway.

Regards,
Szymon

[B00t@]

Hi,

I also have the same issue. I have been running the displaylink.software and HDMI-adapter device for a while without any issues. This setup enabled double displays and has been working as intended. But as for approximate two weeks ago I updated the Macbook, and it stopped working. After the update, the displaylink manger does not recognise the monitors and nothing appears on the manager nor the displays.

I have tried resolving this by running displaylink end-user cleaner, rebooting, installing displaylink manager, rebooting, and pluging in adapter and hdmis. But no progress in this, so thats why I have turned to this forum to see If I can get any help.

Setup:
Macbook Air M1 2020,
MacOs Tahoe 26.3.1 (a)
Wavlink WL-UG6902H (Adapter)
DisplayLink Manager Graphics Connectivity 15.1

[ceiba48]

I am having the same issue with the same set up after the update. Please come out with a fix for this.

[automised_matt]

Hi automised_matt,

I had a quick check of your logs. What is wrong - there are no signs of monitor presence connected to the dock. Does any of the monitors appear when you unplug and plug monitor DP cable or power cycle the monitor?

BTW thanks for the pointers, however "Couldn't read values in CFPrefsPlistSource..." is not an indication of something going wrong here :)

One thing to note: with FileVault enabled you won't be able to use DisplayLink displays on the login screen anyway.

Regards,
Szymon

Thanks, Szymon. I have unplugged and replugged monitor cables, power-cycled monitors, the dock, the mac - all to no avail. The dock is on the latest firmware and was all running well prior to the recent OSX update.

If there are other log entries you want me to look for that could be telling, just let me know 👍.

[tammi]

I have this product and after upgrading to Displaylink Manager version 15.1. it stopped working. Downgrading to version 15.0. fixed it. So something wrong with new version 15.1.

https://eu.targus.com/products/usb-c-universal-quad-4k-docking-station-100-watt-power-delivery-dock570euz

[automised_matt]

I have this product and after upgrading to Displaylink Manager version 15.1. it stopped working. Downgrading to version 15.0. fixed it. So something wrong with new version 15.1.

https://eu.targus.com/products/usb-c-universal-quad-4k-docking-station-100-watt-power-delivery-dock570euz

Thanks, tammi. I just tried the suggested downgrade, but it has made no difference for me, unfortunately :-(

[Szymon]

I have this product and after upgrading to Displaylink Manager version 15.1. it stopped working. Downgrading to version 15.0. fixed it. So something wrong with new version 15.1.

https://eu.targus.com/products/usb-c-universal-quad-4k-docking-station-100-watt-power-delivery-dock570euz

Hi tammi,
Regarding your problem please refer to this thread:
https://www.displaylink.org/forum/showthread.php?t=69861&page=2

Here we discuss an independent issue which is reported on Dell D6000 dock.

Thanks,
Szymon

[Szymon]

Hi automised_matt,

Thanks for the update and additional checks.
I'm going to discuss your case and further actions with engineering - let's continue the discussion via the support ticket you have raised.

Regards,
Szymon

[automised_matt]

I found my problem - and it is my fault. My monitors have 2 x DP ports in each. I did not realise that one port was DP In and the other was DP Out (for daisy chaining). I though both were DP In ports. I had, by chance, plugged the DP cables from the dock into the DP Out ports on both monitors, instead of the DP In ports. That is why they were not registering as being connected to the dock. Once moved to the DP In ports on the monitors, everything worked again... 🤦🏻*♂️

Sorry for any wasted efforts...

[Szymon]

Hello,
I'm glad it works and thank you for sharing the feedback!

Regards
Szymon

[ginopalazzo]

Having the same problem with that anyone in this thread (beside automised_matt :) ):

-Dell D6000
-Macbook Pro M2 Pro 14"
-macOS Tahoe Version 26.4.1 (25E253)
-DisplayLink 16

I tried everything: unplug/plug reboot, clean, reinstall....
Was working fine (with 2 monitors) and suddenly stopped working. In System Report I see my D6000 connected to the usb port:

https://i.postimg.cc/VvD1BsJ2/Screenshot-2026-04-30-at-23-21-55.png

But the only thing that the Dell D6000 does is charge the computer (no monitors, no audio/pendrive).
Does anyone have a clue of what could be happening?
Thanks in advance

[Szymon]

Hi ginopalazzo,

It seems none of USB 3.0 devices appear on the bus, which confirms your observations (no monitors, pendrive).

Are you able to test your dock connecting to another port of your Mac or different Mac / PC?
If the problem persists it could be a hardware fault.

Regards,
Szymon