Thank you for your response.
There was something wrong with updating. Because I had no new installation of NoMachine but I updated existing one.
I found that the NoMachine was connected to the DISPLAY:1003.0 and my Raspberry Pi enviroment DISPLAY was set as 1002.0.
I didn’t know how to align the numbers of DISPLAY variable so I applied the simplest solution. I removed existing configuration files and reinstalled NoMachine.
And everything works as before. And I enjoy the remote pulpit of my Raspberry Pi with NoMachine.
But Thank You again. And you are doing great work with this software!