This error message usually indicates that there is a problem resolving the hostname of the license manager machine. The license server's hostname must be resolvable for MATLAB to connect to it. To test this, we need to use the ping application, which is a command line utility:
Press Ctrl Alt T on the keyboard. If you prefer, there should be something called Terminal in your programs menu. You can search for it by pressing "Windows" key and typing "terminal". Remember, commands in Linux are case sensitive (so upper- or lower-case letters matter).
After launching the command line interface, enter this command:
where hostname is the hostname of the license server as it appears on the SERVER line of your license file. For version R2008a or later, the license file is named network.lic and is found under $MATLAB/licenses.
For versions prior to R2008a, the license file named license.dat and is located in either:
$MATLAB\bin\{win32|win64} (For Windows) $MATLAB/etc (For all other operating systems)
where $MATLAB is your root MATLAB installation directory.
If the output of the above command comes back as 'unreachable' or 'unresolvable', then contact your System Administrator and have them address this issue. Alternatively, if you are unable to resolve the hostname of the license server, but can ping the IP Address of the license server, you can replace hostname in the SERVER line of your local license with the IP Address of the license server. To do so:
1. Navigate to $MATLAB/licenses on your machine. 2. Open network.lic with WordPad (Windows) or TextEdit (Mac). Do not open the file with Notepad. 3. In the SERVER line, the second item is the hostname. Replace this with the IP address. 4. Save the file and launch MATLAB to test if MATLAB was able to connect to the license server.
NOTE: If your license server does not have a static IP, then this workaround will stop working when the DHCP lease is updated. You should contact your license administrator to try and resolve the issue with hostname resolution if your license server does not have a static IP.
If MATLAB is still unable to connect to the license server even though you can ping it successfully, there may be one or more firewalls blocking the connection between the MATLAB client and the MATLAB license server. The license manager communicates on two ports that must be opened through the firewall(s). If there is a firewall running, contact your System Administrator to open the necessary ports in the firewall.
For more information about the port the license manager uses, see the following Article:
For more information about checking your ports, see the Article:
