It seems like there is a problem with loading KEXT, by system utilities. To resolve this case, call:
After it is done, in order to approve the KEXT, access the System Preferences -> Security & Privacy -> General panel on your Mac and click on the ‘Allow’ button (see attachment).
(To get more information, follow this article https://www.nomachine.com/AR01P00962)
Then you need to restart nxserver with command:
Did you upgrade your operating system? If yes, which was your previous version? Logs would be useful. Please follow the guidelines here: https://www.nomachine.com/AR10K00697.
Please send them to forum[at]nomachine[dot]com making sure to reference the title of your topic in the subject.