External monitor gone after 15.2 update

[edelmeier]

I just installed the latest (15.2) MacOS update. Unfortunately, my external screen ( DELL U4919DW conected via USB C) is now not recognized anymore.

Neither is the built-in USB hub, which left me wondering whether it's just this "Allow accessory to connect" window that should be popping up, but somehow isn't...I set the relevant setting for this to a very forgiving value for testing purposes, but no change.

As hinted in a reddit forum, I tried deleting /Library/Preferences/com.apple.windowserver.displays.plist and rebooting, no impact though.

Any ideas what could be done to reactivate my setup?

 

[edelmeier]

Last post here did the trick. While connected to the monitor, pull its power cord. reconnect it. Working again.

 

[FreakinEurekan]

Intel or Apple Silicon?
I presume you've removed & re-seated cable on both ends, tested new cables, tested other USB-C ports on the Mac, NO other devices connected, full shutdown & restart (not just "Reboot")? If not, test all of those first.
Apple Diagnostic?
New User & Safe Mode?

 

[edelmeier]

M1 Silicon. Shut down MAC, started new. Tested other ports.

In fact, this is already resolved, but my post is awaiting moderator approval. I had to unplug the monitor from the power source while connected via USB-C. After re-plugging it, it's recognized again.