Topic: Mac Big Sur: driver not loaded after reboot
Symptom: The audio interface only works directly after driver installation. The usual reboot after driver installation will no longer load the driver, so the audio interface is unavailable. This is reported with macOS 11.4, but also with 11.3.1.
Cause: Not fully clear. According to user feedback this can happen after OS updates, other companies driver updates and RME driver updates.
Underlying cause: It seems that the internal data base of macOS kernel extensions and security allowances gets corrupted. While the driver clearly had been allowed before the OS now acts as if it was not. On reboot, that is.
Fix: has to come from Apple.
Workaround: according to user feedback it is possible to refresh the internal list and bring back the former, working system. Forum user ndc described how to do that (https://forum.rme-audio.de/viewtopic.ph … 60#p170260):
- boot into recovery mode
- open Terminal
- run the kernel extension panic medic boot command by typing:
kmutil trigger-panic-medic --volume-root /Volumes/YOUR_HD_DRIVE_NAME
Default hard drive name is Macintosh HD, where the space has to be omitted. Else use your custom drive name.
This action removes the kext-consent entries. These can now be re-approved after a reboot:
- Reboot into normal mode
- Go to Security&Privacy and allow all items currently not allowed.
- It might be necessary to install the RME driver again to trigger a kext consent entry notice. If you reinstall make sure not to click reboot too early., first finish the driver installation and the Security&Privacy request.