Server side logs have to be collected on the NoMachine server host where the problem occurs:

These are the general steps to collect and send logs:
- Set debug log level manually.
- Reproduce the problem.
- Create the compressed archives of logs.
- Send the archives to NoMachine Support Team by e-mail or ask Support to provide a space for uploading logs if size is too big for an e-mail attachment.

TIP

For v. 6.5 or later When the problem is easily reproducible or if the Support Team requested that, you may clean the logs before starting the procedure above to collect them. Execute:

nxserver --logrotate

Rotated files are saved in the NoMachine var/log/logrotate directory: /usr/NX/log/logrotate on Linux %PROGRAMDATA%\NoMachine\var\log\logrotate on Windows /Library/Application Support/NoMachine/var/log/logrotate on Mac.

Step 1 - Set debug level in server.cfg
Edit /usr/NX/etc/server.cfg, remove the # from the key name (uncomment) and set the following:
SessionLogLevel 7

If the problem affects web sessions, set also:
WebSessionLogLevel 7

Step 2 - Set debug level in node.cfg
Edit /usr/NX/etc/node.cfg, remove the # and set the following:
SessionLogLevel 7
and:
SessionLogClean 0

TIP

It's NOT necessary to restart the server or the NoMachine services, except if this has been requested by the Support Team.

Step 3 - Reproduce the problem
If also client side logs are requested, ensure that the client on the user's computer has the 'Don't delete log files on exit' option checked in the GUI Settings ('Privacy' panel), or that the web session is launched in debug mode (see detailed instructions in paragraphs dedicated to collect client side logs).

Connect to the NoMachine server and reproduce the problem.

Once reproduced:
- collect server side logs.
- collect client side logs if requested.

Step 4 - Create the compressed server side logs archive
Create a compressed tar.gz archive of the /usr/NX/var/log directory:

Step 5 - Send the server logs archive to the Support Team

Step 1 - Set debug level in server.cfg
Edit /usr/NX/etc/server.cfg, remove the # from the key name (uncomment) and set the following:
SessionLogLevel 7

Step 2 - Set debug level in node.cfg
Edit /usr/NX/etc/node.cfg, remove the # from the key name and set the following:
SessionLogLevel 7
and:
SessionLogClean 0

Step 3 - Reproduce the problem
If also client side logs are requested, ensure that the client on the user's computer has the 'Don't delete log files on exit' option checked in the GUI Settings ('Privacy' panel), or that the web session is launched in debug mode (see detailed instructions in paragraphs dedicated to collect client side logs).

Connect to the NoMachine server and reproduce the problem.

Once reproduced:
- collect logs on the Terminal Server Node host.
- collect client side logs if requested.

Step 4 - Create the compressed server side logs archive
Create a compressed tar.gz archive of the /usr/NX/var/log directory:

Step 5 - Send the Terminal Server Node logs archive to the Support Team

Step 1 - Set debug level in server.cfg
Edit /Applications/NoMachine.app/Contents/Frameworks/etc/server.cfg, remove the # from the key name (uncomment) and set the following:
SessionLogLevel 7

If the problem affects web sessions, set also:
WebSessionLogLevel 7

Step 2 - Set debug level in node.cfg
Edit /Applications/NoMachine.app/Contents/Frameworks/etc/node.cfg, remove the # from the key name and set the following:
SessionLogLevel 7
and:
SessionLogClean 0

TIP

It's NOT necessary to restart the server or the NoMachine services, except if this has been requested by the Support Team.

Step 3 - Reproduce the problem
If also client side logs are requested, ensure that the client on the user's computer has the 'Don't delete log files on exit' option checked in the GUI Settings ('Privacy' panel), or that the web session is launched in debug mode (see detailed instructions in paragraphs dedicated to collect client side logs).

Connect to the NoMachine server and reproduce the problem.

Once reproduced:
- collect server side logs.
- collect client side logs if requested.

Step 4 - Create the compressed server side logs archive
Create a compressed tar.gz archive of the /Library/Application Support/NoMachine/var/log directory:
Navigate with the Finder till the /Library/Application Support/NoMachine/var/log directory. Compress this folder: control-click or right-click the folder and then choose 'Create Archive' from the pop-up menu.

As an alternative, create the archive from command line:

Step 5 - Send the server logs archive to the Support Team

Step 1 - Set debug level in server.cfg
Copy the InstallationDirectory/NoMachine/etc/server.cfg file in a temporary folder and open the file with an editor like WordPad. This is necessary for being able to edit the file.

Edit the copy of the server.cfg file, remove the # from the key name (uncomment) and set the following:
SessionLogLevel 7

If the problem affects web sessions, set also:
WebSessionLogLevel 7

Copy the modified server.cfg file to InstallationDirectory/NoMachine/etc/server.cfg. Administrative privileges are required.

Step 2 - Set debug level in node.cfg
Copy the InstallationDirectory/NoMachine/etc/node.cfg file in a temporary folder and open the file with an editor like WordPad. This is necessary for being able to edit the file.

Edit the copy of the node.cfg file, remove the # from the key name and set the following:
SessionLogLevel 7
and:
SessionLogClean 0

Copy the modified node.cfg file to InstallationDirectory/NoMachine/etc/node.cfg. Administrative privileges are required.

TIP

It's NOT necessary to restart the server or the NoMachine services, except if this has been requested by the Support Team.

Step 3 - Reproduce the problem
If also client side logs are requested, ensure that the client on the user's computer has the 'Don't delete log files on exit' option checked in the GUI Settings ('Privacy' panel), or that the web session is launched in debug mode (see detailed instructions in paragraphs dedicated to collect client side logs).

Connect to the NoMachine server and reproduce the problem.

Once reproduced:
- collect server side logs.
- collect client side logs if requested.

Step 4 - Create the compressed server side logs archive
Create a compressed archive of the NoMachine's /var/log directory.

The NoMachine /var/log directory is:
%PROGRAMDATA%/NoMachine/var/log on Windows Vista, 7, 8, 8.1 and 10.
Documents and Settings/All Users/NoMachine/var/log on Windows XP.

To compress it, right-click the file or folder, point to Send To, and then click Compressed (zipped) Folder.

Step 5 - Send the server logs archive to the Support Team

Since version 6.12, a new option is available to enable debug log level for the already running 'nxserver --daemon' process. Such process is in charge of specific operations like to detect the physical display, start/stop the NoMachine web server nxhtd, create new virtual desktops on Linux and more. Enabling this debug mode doesn't require to restart the server.

To enable this debug on Linux and macOS, open a terminal and execute:

If you are the root user, run the command above without 'sudo'.

To disable this debug mode:

To enable this debug on Windows, open a CMD console as administrator and move to the 'bin' folder under the NoMachine installation, e.g:

Then execute:

To disable the debug mode:

TIP

The 'daemon' option can be used in conjuction with the other --enable/--disable options of the 'nxserver --debug' command. Detailed usage of such command is available in the Guide to collect server side logs automatically: https://www.nomachine.com/DT10O00162.

COLLECT AND SEND CLIENT SIDE LOGS 2. How to Collect Client Logs from Users' Devices TIP When the connection terminates with an error, the client shows a dialog with a short error message and allows to save logs of that problem into a directory. In this case: - Save client logs when prompted to do it. - Compress the directory containing logs. - Send the archive to NoMachine Support Team by e-mail. When the connection doesn't terminate with an error but shows an unexpected behavior to be investigated (e.g. black or frozen screen, wrong keyboard mapping etc ...) the client cannot issue the dialog to save error logs. In this case, or if requested by the NoMachine Support Team, you have to retrieve logs manually as explained in the next paragraphs. Collecting client side logs manually requires to make the following operations on the user's computer from which the connection is started: - launch the NoMachine User Interface on the user's computer from Programs or Menu - click on Settings to open Player preferences and click on the Privacy tab - select the Don't delete log files on exit checkbox - Connect to the server and reproduce the problem. - Compress the user's home/.nx directory containing logs. - Send the compressed logs archive to NoMachine Support Team by e-mail. If the user instead runs sessions via web, launch the web session in debug mode as explained in the dedicated paragraph. 2.1. Client on Linux Create a compressed tar.gz archive of the .nx directory in the user's home on his/her computer: $ tar -cvp --exclude 'cache*' --exclude 'images' --exclude 'temp' $HOME/.nx | gzip -c >nxdir.tar.gz or, if you are not the owner of this user's home, run the command with sudo: $ sudo tar -cvp --exclude 'cache*' --exclude 'images' --exclude 'temp' $HOME/.nx | gzip -c >nxdir.tar.gz 2.2. Client on Mac Create a compressed archive of the .nx directory in the user's home. Navigate with the Finder till the .nx directory. To reduce the size of the archive, remove cache, images and recording sub-directories under .nx before creating the compressed folder. Compress this folder: control-click or right-click the folder and then choose 'Create Archive' from the pop-up menu. As an alternative, you may create a tar.gz archive from command line. Run in a console: $ tar -cvp --exclude 'cache*' --exclude 'images' --exclude 'temp' $HOME/.nx | gzip -c >nxdir.tar.gz or, if you are not the owner of this user's home, run the command with sudo: $ sudo tar -cvp --exclude 'cache*' --exclude 'images' --exclude 'temp' $HOME/.nx | gzip -c >nxdir.tar.gz 2.3. Client on Windows Create a compressed archive of the .nx directory in the user's home. The .nx folder is hidden. To find it, write the following in the address bar or the file browser: %USERPROFILE%\.nx As an alternative, you may navigate through the computer folder till the user's home and digit .nx in the navigation toolbar to reach this hidden folder. Path can be similar to: C:/Users/nomachine/.nx To reduce the size of the archive, remove cache, images and recording sub-directories under .nx before creating the compressed folder. Then compress the .nx directory: right-click the file or folder, point to Send To, and then click Compressed (zipped) Folder. Provide also the nxtrace.log if present. The nxtrace.log file is generated only in case of a sudden termination of any of the NoMachine programs. It's stored in: %PROGRAMDATA%/NoMachine/var/log on Windows Vista, 7, 8, 8.1, 10 or Documents and Settings/All Users/NoMachine/var/log on Windows XP. You may also search it on your computer by using the Windows tool: use the Search box on the Start menu to find programs, type there nxtrace.log to locate this file. 2.4. Client on Android Tablets/Smartphones Please refer to instructions here: https://www.nomachine.com/AR04M00843 2.5. Client on iOS Devices Please refer to instructions here: http://www.nomachine.com/AR07N00897 2.6. Browser (Web Sessions) Logs are stored in the browser's local storage, so the user's browser needs to have Local Storage support. If yes: Step 1 - Point your browser to the webplayer application and run it in debug mode: https://server:port/nxwebplayer?logging=start For example: https://testdrive.nomachine.com:4443/nxwebplayer?logging=start Step 2- Log-in to NoMachine and perform all steps requested to reproduce the problem. Once the problem is reproduced, retrieve logs by typing in the browser's navigation bar: https://server:port/nxwebplayer?logging=get For example: https://testdrive.nomachine.com:4443/nxwebplayer?logging=get This will disconnect the session and display the logs page. Step 4 -Click on the 'Download' button in the upper right corner of the page to download and save the log file. Step 5 - Send the log file to NoMachine Support Team by e-mail. Please be sure to include ID of the enquiry in the subject of your e-mail. For turning off the debug mode, type in the browser's navigation bar the action to stop the debug mode, for example: https://testdrive.nomachine.com:4443/nxwebplayer?logging=stop 3. How to Locate the Connection Settings File (.nxs) Configuration of the client's session (namely the connection file .nxs) is stored by default in /Documents/NoMachine. To verify where the session files are effectively saved, run the NoMachine client and click on Settings ->Folder. Check path set for 'Connections and recordings'. OTHERS 4. How to Gather a Stacktrace In many cases a core file debugged outside of the original environment doesn't provide all the necessary information. That's why it's important to gather the stacktrace onsite and send it to the Support Team for analysis. 4.1. On Linux Please refer to instructions here for debugging a core file onsite: https://www.nomachine.com/AR09L00810 To know which application has generated the core, run from a console: file PATH_TO_CORE_FILE 4.2. On Mac On Mac you need to reetrieve stacks automatically generated by the system. Diagnostic reports are stored in: a) ~/Library/Logs/DiagnosticReports and: b) /Library/Logs/DiagnosticReports Note that path a) and b) are different. Stacks for NoMachine programs are prefixed with 'nx', retrieve them from directories a) and b) if any and send the diagnostic reports as e-mail attachment. 4.3. On Windows In case of a sudden termination, NoMachine programs generate on Windows the nxtrace.log file. This file is placed in the following directory: %PROGRAMDATA%/NoMachine/var/log on Windows Vista, 7, 8, 8.1, 10 Documents and Settings/All Users/NoMachine/var/log on Windows XP. Otherwise you may search for nxtrace.log on your computer by using the Windows tool: use the Search box on the Start menu to find programs, type there nxtrace.log to locate this file. 5. How to Debug a CPU Consuming Process on Linux Please refer to instructions here: https://www.nomachine.com/AR09L00809 6. How to Debug the NoMachine Monitor on Linux Please refer to instructions here: https://www.nomachine.com/AR03O00922 7. Troubleshooting Troubleshooting issues caused by system resources exceeded on Linux https://www.nomachine.com/AR04O00927 Troubleshooting LDAP and PAM issues on Linux for connections by NX protocol https://www.nomachine.com/AR08M00857 Troubleshooting NoMachine in a Active Directory Domain https://www.nomachine.com/AR04O00925 Troubleshooting problems when enabling VirtualGL support for NoMachine virtual desktops https://www.nomachine.com/AR04Q01024 How to solve 'session negotiation failed, application terminated prematurely' https://www.nomachine.com/AR08N00898 Troubleshooting microphone issues in KDE 4 https://www.nomachine.com/AR11P01006 Troubleshooting audio problems in NoMachine sessions on CentOS/RHEL https://www.nomachine.com/AR10Q01048 Troubleshooting automatic updates https://www.nomachine.com/AR03Q01021