Hello
The topic and trouble report you found is a bug that was happening only for NoMachine version 6.7.6, so it should not be the case here.
The most probable cause here is an update from a non-administrator account. We have tested this scenario on previous versions, and indeed the result was the “no physical desktop” screen. What the tests also showed was that a simple machine restart would fix the problem and the connections was possible again.
Of course this may not be the case here, so let’s start with a restart. Then if the problem still persists please do:
sudo /etc/NX/nxserver --shutdown
Then navigate the OSX options to the “Security and Privacy”, the “Privacy” tab and from both “Accessibility” and “Screen recording” options please remove (by clicking ‘-‘ button, not just by disabling the checkbox) any and all “NoMachine”, “nxnode” or “nxserver” entries. then please do:
sudo /etc/NX/nxserver --startup
and accept any requests for permissions.
/Mth