Mac cannot detect external audio driver
The fact that Safe Mode works suggests that the old drivers for your external audio interface are no longer compatible with the newer OS. Check on the manufacturer's website for a new version, and/or follow any instructions for uninstalling the old driver.

Some audio interfaces are "CoreAudio compliant" and can actually work fine without any additional drivers to those built-in to MacOS. After you've removed the old drivers, it's worth seeing if it will work without installing new ones.