Hi,
I have trouble connecting from Ubuntu 16.04 to a server that is running on Ubuntu 18.04 (free version of NoMachine 6.2.4 on both machines). I have other servers to which I can connect with no problems.
On the first try, I was still able to choose the server’s screen resolution but aborted due to other things I had to do here in the lab. When trying again to connect to the server, it asks for the password and seems to connect. The cursor gets black when hovering over the NoMachine window but the window stays white. I tried uninstalling NoMachine on the server, but the problem remains. My guess is, that NoMachine did not like me aborting during the first attempt to connect, but, unfortunately, I have no clue how to rescue it.