After upgrading NoMachine (free) or the Enterprise Desktop to v.  6.10.12 on macOS, audio is no longer available and it's no longer possible to connect disks from local to remote in a NoMachine session. The service to forward network port is also affected. In some cases, the problem occurs only after rebooting the system.

As a temporary workaround perform the following steps.

1) Remove leftovers after the NoMachine update

sudo find /Library/Application\ Support/NoMachine/Extensions/ -name "*.temporary" -delete -print

and remove the following NoMachine *.temporary files.

On macOS 10.15:

sudo rm /Library/Extensions/nxaudio.kext/Contents/MacOS/nxaudio.temporary

sudo rm /Library/Extensions/nxaudio.kext/Contents/_CodeSignature/CodeResources.temporary
 

On previous versions of macOS:

sudo rm /System/Library/Extensions/nxaudio.kext/Contents/MacOS/nxaudio.temporary

sudo rm /System/Library/Extensions/nxaudio.kext/Contents/_CodeSignature/CodeResources.temporary

2) Rebuild system kext cache to properly load kexts after reboot:

sudo kextcache --clear-staging

sudo kextcache -system-caches

3) Restart NoMachine:

sudo /etc/NX/nxserver --restart

As an alternative, uninstall and install NoMachine.