“No available desktop on this server” with Dummy Displayport

[netmind]

I’ve been using a dummy displayport adapter with NoMachine for over a year fine, but about a week ago after some Ubuntu and possibly a NoMachine updates, I can no longer connect and keep on getting “No avail desktop…” error.

If I plug in a monitor, I can see that both displays are detected (the monitor + the dummy) and I can connect with NoMachine fine (even if I unplug the monitor).  However if no monitor is present during bootup – no go.

What’s best way to resolve?  I’m ok with reinstall if that’s the simplest.

OS:  Ubuntu Desktop 22.04.03 (but with no monitor connected)

NoMachine: 8.10.1

 

[Macrobiotic]

I’ve had the same issue with Ubuntu 23.10

I’m not sure if it’s the dummy adapter or 8.10.1

If I sign in to the OS and then disconnect the external monitor, I’m able to access the machine.
It seems the problem only appears on the Lock Screen.

[Macrobiotic]

After a bit more testing, I’ve found that the issue may be that the NoMachine agent doesn’t run on the Lock Screen after startup.

It’s necessary to log in once as a local user, and only then does the agent run.

I’m going to check if it’s possible to work around this issue by making the machine log in automatically to the OS and then let the screen lock itself. (Not good from a security perspective, but better than losing remote access fully.)

[Macrobiotic]

I’ve just completed a successful test by setting the machine to log in automatically on start up.

That’s a viable work-around for me, as the machines are physically secured. It may not work for everyone.

This would appear to confirm my suspicion that the issue is related to NoMachine 8.10.1 not running correctly on the Lock Screen after startup.

[netmind]

Thanks, I can confirm this works for me too and likewise feel totally good about this.

I really hope this isn’t the only way now to use NoMachine with a dummy plug instead of a monitor.

@NoMachine – Seems to me this is a regression introduced into 8.10.1 with the security stuff.  Or at the least a designed change in behaviour that needs to be documented with recommended practice.

[Britgirl]

Everyone, please follow the workaround posted in another issue, but related:

How to speed up NM server startup at boot

Thanks!

[Author]

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