After a recent OS version update to SUSE Slowroll (a Tumbleweed derivative), unable to connect from Window 10 machine. Get the Error 108 message at the very last step in physical display connection process.
Trying to connect from a SUSE Leap 15.5 Linux machine to the same Slowroll server produces the same result, but with error 104. Session log has first mention of error saying
290.885 ProxySession/ProxySession: ERROR! Session failure in stage ‘StateWaitingProxyVersion’.
Windows 10 client: NoMachine Enterprise Client 8.11.3
Linux Server: NoMachine free 8.11.3_4_x86_64 with KDE desktop
Linux Client: SUSE Leap 15.5 (KDE desktop) NoMachine 8.11.3