For those who have issues with recent versions of NX Studio. Don't install FW version 4.0.

Firmware 4.0 requires that NX Studio be 1.4 or newer.

What Firmware-related object please ?

Z9 FW ver. 4.0. Nikon states that Ver. 4.0 requires Studio NX to be 1.4 or higher. I and others have not seen a fully function version since 1.2.2.

I am in the same boat not had a lot of luck with latest Studio NX versions