Wed Dec 02, 2020 4:18 pm
MY SOLUTION - UltraStudio Recorder 3G and Big Sur
Hello all. I had Desktop Video 11.7 installed on Catalina and then upgraded to Big Sur. I experienced the same issue as everyone else. The recorder was recognized, but all I saw was a black screen in OBS. I tried installing 12.0b1 and got the same thing. I completely uninstalled several times and reinstalled, but it was still the same.
Then I noticed that the uninstall left 3 kernal extensions on my system:
Blackmagic_Multibridge_Driver.kext
BlackmagicIO.kext
BlackmagicUsbIO.kext
So, I thought about getting rid of those. To do that, you have to boot into recovery mode, disable SIP, force delete the kernal extensions, then reenable SIP. Once I did all of this and then installed 12.0b1, it WORKED! Desktop Video recognizes the recorder and the picture displays correctly in OBS, using either SDI of HDMI.
Here were the steps I took:
1. Uninstall Video Desktop using the uninstall program.
2. Boot into Recovery Mode (command-r)
3. Open Terminal to disable SIP: At the prompt enter this command: csrutil disable
4. You will get a message that SIP has been disabled.
5. Then enter reboot.
6. Once you reboot, open Terminal and force delete the kernal extensions. In my case, the commands looked like this for the three extensions:
sudo rm -rf /Library/StagedExtensions/Library/Extensions/Blackmagic_Multibridge_Driver.kext
sudo rm -rf /Library/StagedExtensions/Library/Extensions/BlackmagicIO.kext
sudo rm -rf /Library/StagedExtensions/Library/Extensions/BlackmagicUsbIO.kext
7. After deleting the extensions, I rebooted in Recovery Mode (command-r)
8. Open Terminal to enable SIP: At the prompt enter this command: csrutil enable
9. Then enter reboot.
9. Once rebooted, install Video Desktop. I used the Beta, 12.0b1
10. If Desktop Video then says "No Desktop Device Detected" you have to go to System Preferences>Security & Privacy>General and the select "App Store and identified developers” and then “Allow” Blackmagic Design in the pop-up window. You might have to restart after that.
It worked for me, which made me think the leftover kernal extensions were the problem going from Catalina to Big Sur. I hope it works for you. I am glad to be back up and running with my 3G under Big Sur!