Black screen problem

[mrosing]

Free version 6.9.2 both client and server – physical display – ubuntu 18.04 (both sides) – gnome both sides

I have tried several ways to attempt to fix a black screen on connection and all have failed.  The first thing I tried was to reload h.264 library codecs on both client and server.  I then edited node.cfg so it could find libGL.so and restarted the server.  Then I found the log files and noticed it could not find libpam.so, so I edited nxexec so it pointed to the right place.  I edited the server.cfg and node.cfg according to https://www.nomachine.com/DT10O00163 but it really didn’t change the log of the error:

5457 5457 11:31:41 073.074 Process: ERROR! Cannot get information for user id ‘10699’.
5457 5457 11:31:41 073.089 Process: ERROR! Error is 2, No such file or directory.
5457 5457 11:31:41 073.092 HostGetUserInfoByUid: WARNING! Failed to get process user information.

Searching for this error I found this forum.  It is possible all the libraries nx is looking for are one more level deep (in /usr/lib/x86_64-linux-gnu) and I just need to fix something simple.    Any ideas on how to fix this?

Thanks

Mike

[kroy]

It is not advisable to make changes to the binary files. Please uninstall, remove NoMachine directories and install again. If problem with black screen shows again – use this tip: https://www.nomachine.com/AR03P00973

[mrosing]

I uninstalled and re-installed on both sides and still got black screen.  Then I turned off gdm, and still got a black screen.  There are no errors in the logs on the server side, but the client side shows:

19176 20295 08:20:14 390.375 ServerNetworkInfoHandler: WARNING! Obtaining network data failed.

Rebooting to run level 3 via remote vpn is problematic.  Is there a way to capture more verbose info to help debug this?

Thanks.

[mrosing]

We changed to a different computer which is actually headless.  This time I got a set of log files, and the message:

The session negotiation failed.

Error: Cannot create a new display, please contact your system administrator

The log files are attached.

Hopefully there is a clue on how to make this work.

[mrosing]

So the files didn’t make it, but it looks like that doesn’t matter.  I ran nxexec –auth directly and got the following:

/usr/NX/bin/nxexec –auth
Username:mrosing
Please wait…
Please wait…
Please wait…
ERROR: Internal exception.
4689 4689 08:12:35 228 nxexecPAMCheckCredentials: ERROR!Authentication failed with error 7.
Login failed.

There is nothing in the log from this interaction.  How can I turn on debugging to figure out why this is happening?

Thanks!

Mike

[Britgirl]

Can you send any files that didn’t upload to forum[at]nomachine[dot]com? Please put the title of your topic as the subject, thanks!

[mrosing]

I put everything back to the original (and latest NoMachine 6.9.2), plugged in a terminal to the box with the black screen, and now it works fine.  This is definitely a user error problem, thank you for the help!

[Britgirl]

There is also an article in the knowledge base handling this issue:

How to solve black screen on headless machines
https://www.nomachine.com/AR03P00973

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