No monitors detected after macOS Tahoe 26.3.1 update - 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.