I was able to run NX server on my remote Ubuntu headless system and let NoMachine create the virtual display till yesterday. After updating my Nvidia driver (to 530.30.02), I could no longer access to my remote server. Tried updating NoMachine to the latest available for Linux (nomachine_8.4.2_1_x86_64), and also updated NoMachine on my local Windows laptop, but that did not help. Here is part of the session log message:
27024 9532 09:52:18 249.107 ClientSession: Going to query the server for available services.
27024 9532 09:52:20 156.049 Connection: Connection at 0x03b8ac10 failed.
27024 9532 09:52:20 156.049 ClientSession: Runnable at 0x03b8ac10 caused the session at 0x00cce778 to fail.
27024 9532 09:52:20 156.049 ClientSession: Failing reason is ‘The session negotiation failed.
Error: Cannot create a new display, please contact your system administrator’.
Do you know how this could be fixed?