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.
Kind regards,
Thomas