• Registered: 2021-08-04
  • Posts: 2

Topic: macOS Big Sur and third-party driver loading issues? Possible solution

Hi. I recently found the closed Sticky post "Mac Big Sur: driver not loaded after reboot", while searching for solutions to similar issues with Blackmagic Desktop Video drivers.

Since this sticky post is closed, I figured I would post a new thread here.

We had multiple macOS Big Sur systems at work that struggled loading Blackmagic Desktop Video drivers and ATTO 10 Gb network drivers at boot, even though loading manually with "kmutil load -p /Library/Extensions/BlackmagicIO.kext" and "kmutil load -p /Library/Extensions/Decklink-driver.kext" and "kmutil load -p /Library/Extensions/ATTOFastFrame.kext"worked fine.

After a lot of troubleshooting, it turns out that it was actually an old "Dropbox.kext" from 2019 in "/Library/Extensions" that prevented "Blackmagic Desktop Video" and other third-party drivers from loading at boot. Once I deleted this old "Dropbox.kext", other drivers (Blackmagic and ATTO) loaded automatically right away, even without a reboot.

Might be worth checking, since Dropbox is a pretty popular and common app to have installed.

I hope this helps someone out there. smile

Kind regards,
Thomas

2 Reply by MC

  • MC
  • MC
  • Administrator
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  • From: Germany/Thailand
  • Registered: 2007-04-06
  • Posts: 25,436

Re: macOS Big Sur and third-party driver loading issues? Possible solution

Thanks. Unfortunately we at RME never saw this issue on our machines so can not check if that will work.

Regards
Matthias Carstens
RME

MC's Website

  • From: Adelaide - Australia
  • Registered: 2007-05-01
  • Posts: 451

Re: macOS Big Sur and third-party driver loading issues? Possible solution

I definitely had the same problem re the BlackMagic kext files. 
I don't have the Dropbox kext in the extensions folder.

However, once I removed the BlackMagic extensions (had to disable SIP temporarily to actually achieve this),
Then went through the process in the thread, "Mac Big Sur: driver not loaded after reboot".

It had another really great side effect with Logic and Komplete Kontrol keyboards. Since BigSur 11.4, transport control in Logic from the KK keyboard has been broken, but after all this kext kerfuffle, it's working again.

Seems like these latest MacOS updates have been very problematic for a lot of people.

----------------
Matt McKenzie-Smith (UFXII, UFX, Babyface) MacStudioUltra OS13.2.1
----------------

mattrixx's Website

  • Registered: 2021-08-04
  • Posts: 2

Re: macOS Big Sur and third-party driver loading issues? Possible solution

Hi again. It turns out simply removing an other third-party kext in /Library/Extensions triggers macOS to immediately load other third-party kexts still present. After a reboot, they stop loading again.

Final solution was as already stated in the sticky, to run through the steps again.

1. Reboot into recovery mode
2. Run the following command in Terminal:

kmutil trigger-panic-medic --volume-root /Volumes/Macintosh\ HD

3. Reboot
4. Install third-party driver again, which will trigger a new approval of all third-party kexts.
5. Do an other reboot as requested by System Preferences Security and Privacy, and now all drivers should load at boot

I have reported back to Apple support about this, and hope they find a way to fix whatever is going wrong at the moment with the kernelmanagerd process.