UltraStudio 4k Extreme not recognized in Sequoia

I just did a clean install, upgrading my OS to Sequoia. All of a sudden, my UltraStudio 4k Extreme is no longer recognized by Desktop video. I started off with 14.5 (Uninstalled/reinstalled 2x) Then downgraded to 14.4.1. Do I need to keep going lower in versions?
(I've unplugged/re-plugged multiple times; I've also confirmed that I've enabled all options/extensions)
When I do a "system report," I can see that the Thunderbolt 3 cable is seeing the 4k Extreme, but Desktop Video does not see anything.

Try 12.9.

12.9 solved my problem.
Thank you so much!

I am having the same issue
My new Ultrastudio $k Mini worked correctly yesterday, on DesktopVideo 14.5 and Mac OS 13.???

Today I updated Mac OS to 15.3.2 and I cannt get the Ultrastudio recognized in Desktop Video
I tried, uninstalling of Desktop Video and testing, 12.1, 12.5, 12.9, 14.0.1, 14.3 and 14.5

Before every installation I did an uninstall end removed left over Library fils as explained in other threads.

Nithing works, the launch of the helperapp in the Terminal /Library/Application Support/Blackmagic Design/Blackmagic DeckLink/DesktopVideoHelper does not launch discover the Ultrastudio either.

also tried toggling extensions on and off (with restart in between)

Nothing

I do have a Decklink Mini Monitor 4k PCI card (in a Thunderbold PCI chassis) and I can get that card discovered with the same identical settings and cables that cannot find the Ultrastudio

on DesktopVideo 14.5 I do have to launch /Library/Application Support/Blackmagic Design/Blackmagic DeckLink/DesktopVideoHelper via an alias after each disconnect or reboot but alt least it's somhow working

as for the Ultrastudio 4k Mini - Nothing works it definitely communicates differently

got 3 more new Thunderbold 240W cable today, that did unfortunately not change anything.

It looks to me as if the Ultrastudio does not receive the "wake-up-signal" from my Macbook, as identical Desktop Video installations, extensions, cables and OS on the same Thunderbold port do work with
a Decklink 4k Monitor PCI card inside a Thunderbold OWC chassis.

I read the "try 12.9" solution but it does not work for me (after clean reinstall and Library files removal).

Try 12.9.

Desktop Video 12.9? With Sequoia? And it works?
Damn. Thanks Uli. I would not have considered going back that far.

Sequoia is pretty evil on Securities & Permissions. I'm not sure what the solution is in being able to overcome it and install external apps and drivers like this.

Just got it to work. Mac Pro running Sequoia 15.4 with Desktop 14.5 and a Decklink 4K Extreme 12G.

I had been struggling with this and found a solution, thanks to a video posted by Josh Mitchell titled "Mac OS Sequoia Fix Blackmagic No Desktop Video Detected" on YouTube (Forum rejected my URL).

Basically uninstall BM Desktop. Then re-install, but when it prompts you about the system settings, don't click "OK." Click on "Open Settings" and toggle on the extension it opens for you. It prompts you for your password, then the same prompt comes up again with the "OK or Open Settings". Again, don't click "OK" click "Open Settings" and toggle on the extension in Login Items also. If the Login Items extension doesn't pop up (it didn't for me), go to Login Items and then scroll down to Driver Extension (it should have a sub heading with Blackmagic in it) and toggle it on. Then enter your password again and then click done. After restarting it should recognize the card.

Shout out to Josh Mitchell for posting the video on youtube.

Just got it to work. Mac Pro running Sequoia 15.4 with Desktop 14.5 and a Decklink 4K Extreme 12G.

I had been struggling with this and found a solution, thanks to a video posted by Josh Mitchell titled "Mac OS Sequoia Fix Blackmagic No Desktop Video Detected" on YouTube (Forum rejected my URL).

Let's see if this sticks: