Black screen connecting to NX 6.7.6 on Linux

[pavlos]

Two days ago I upgraded my Linux systems to 6.7.6 (from 6.6.8 I think). Now, when I try to connect to my headless systems, I get the black screen. But if I temporarily connect a physical monitor, then I can see the display of the remote system. Or if I connect a VGA dummy plug (emulates a physical monitor) I can see the display of the remote system. I’m positive I did not have that issue before 6.7.6 /etc/NX/nxserver –restart on remote 1 or 2 did not resolve the issue. And I cannot d/l the 6.6.8_deb to revert back.

Local system: win10, free, NX 6.7.6

remote 1: Mint 19.1, MATE DE, lightdm, headless

remote 2: Linux MX 18.2, XFCE DE, lightdm, headless

Thanks

 

 

[wazoo42]

I ran into the same issue connecting from my Win10 laptop to Ubuntu 18.04 after updating both to NX 6.7.6. Restarting the server on both did not fix the issue, but logging into the Ubuntu box and running –shutdown, followed by –startup fixed it for me and I now have full video.

[fra81]

Hi,

we are aware of the issue which is due to incorrect info reported by the X RandR extension on some headless machines. Besides the workarounds you already mentioned, you can use also this one: https://www.nomachine.com/AR03P00973.

If you’d like to receive a patched version to test, please write to forum[at]nomachine[dot]com.

[lipigl]

I am getting the same behavior on a remote with Ubuntu 16.04 (ARM), Unity, lightdm, headless. I get a black screen until I plug an HDMI monitor on the remote device, then it works OK. Restarting nxserver does not help. The problem was not present with the previous version.

I have sent an email asking for the patched version.

[pavlos]

@fra81 … I sent email, ty.

 

[GranMain]

Hi…what you mean is for me to press the escape key upon startup and then select Linux Mint 18.3 (top selection on the list)  I have tried that, on one occasion there was an error about being unable to start the X server (or something like that) due to an internal error with graphics.

[shootdavyd]

Hi! The same problem – black screen. Two days ago I was installed NoMachine Free at first time on Ubuntu 18.04. Everything was perfect, all connections from Elementary OS 5.0 and Android was clear (both free version). Today there was a white screen with the hint “unknown codec”. So, I tried to connect via VNC, it was succeeded, so I manually change codec to H264, and disable Wayland. After that I got a black screen. But now, when i connected to remote machine, i see 2 displays – “0” is a black screen from NoMachine, and “1” – from VNC. The problem is, that all opened windows on display “1” (programs, terminals, etc…) opens in display “0” (I see it in task manager), except NoMachine client and server windows, they are opens normally. So, what am I doing wrong? And how fix it?

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[Britgirl]

This is the Trouble Report related to the issue reported here: https://www.nomachine.com/TR05Q09323. You can sign up to receive a notification when a fix has been officially released in an upcoming update. In the meantime, we will reach out to you individually with a hotfix.

[fra81]

The problem is, that all opened windows on display “1” (programs, terminals, etc…) opens in display “0” (I see it in task manager), except NoMachine client and server windows, they are opens normally. So, what am I doing wrong? And how fix it?

I assume that both desktops are owned by the same system user. In that case, how the display to connect to is chosen depends on the application. What you can do is starting the second desktop as a different user. Not sure if you can configure those applications to behave differently.

[pavlos]

@fra81

I d/l the patched version. Tried to install via GDebi, it would not since the patched version 6.7.6-1 is prior to the existing 6.7.6-14. Then, I sudo dpkg -i patched version, it installed fine. I disconnected the monitor on remote 2, then from the local machine I was able to connect to remote 2 with display … good. I rebooted remote 2 and was able to connect again and have display. So this patch works. See attached a screenshot of the install process.

Thank you for your help.

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[ntms]

I have 2 Ubuntu machines on remote Vmware. Over a 6 months they both work correctly. I have install the version 6.7.6. This is the free version.

I am using Win10 and macOS to access 2 remote ubuntu machines. Since 2 days when I connect I got a white blank screen. I cannot see remote ubuntu login page. How can I download any patch to correct the issue? Thanks

[Britgirl]

Please refer to the topic you already submitted: https://forums.nomachine.com/topic/white-screen-after-connection

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