Hi,
I also had some problems with the driver in Big Sur. The answer was 'Big Sur is not supported yet, but it's always good to receive such info' but didnt solve anything !
sudo kextload -v /Library/Extensions/Line6Audio.kext
Executing: /usr/bin/kmutil load -p /Library/Extensions/Line6Audio.kext
Error Domain=KMErrorDomain Code=29 "Authenticating extension failed: Kext com.line6.driver.xtaudio v7.6.8 in executable kext bundle com.line6.driver.xtaudio at /Library/Extensions/Line6Audio.kext:
Authenticating extension failed: Bad code signature" UserInfo={NSLocalizedDescription=Authenticating extension failed: Kext com.line6.driver.xtaudio v7.6.8 in executable kext bundle com.line6.driver.xtaudio at /Library/Extensions/Line6Audio.kext:
Authenticating extension failed: Bad code signature}
also tried
sudo spctl --master-disable
My UX2 is blinking the freaking red lights again ! Damn...
please throw a quick answer if you find out the solution in anyhow !