License Manager Error -95 indicates that MATLAB cannot resolve the hostname of the computer that is running the network license manager.
This issue can occur even if the license manager is running.
To verify that the license file contains a resolvable hostname, open the license file in a text editor. The license file location varies depending upon operating system and version:
Windows: C:\Program Files\MATLAB\R20***\licenses\network.lic
Linux: /usr/local/MATLAB/R20***/licenses/network.lic
macOS: /Applications/MATLAB_R20***.app/licenses/network.lic
In the license file will be a line that starts with the word SERVER followed by the hostname of the license server or the IP address of the license server. Generally this issue occurs when there is a hostname present and that name is not resolvable.
For local license managers, you may also see the term "this_host". This means that the license manager will use the current hostname. This hostname can be retrieved by running the command "hostname" from a terminal or command prompt. It is recommended to change this to the actual hostname instead of this_host.
To confirm that the hostname is resolvable:
- Open command prompt or terminal
- Run the following command (replace "hostname" with hostname of license server)
ping hostname
If the output of the command is "unknown host", MATLAB will not be able to connect to the license manager. You will need to change the hostname listed on the SERVER line of the license file, or use the IP address of the license server.
If the license manager is running locally, you can resolve this issue by making the hostname resolvable. To do so, you can modify the system's host file. Please check with your IT department before modifying your hosts file.
C:\Windows\system32\drivers\etc\hosts (Windows)
/etc/hosts (Linux/Mac)
To make the hostname resolvable, add it to the loopback address line. Generally this line ends with the value localhost or localhost.localdomain. For example, you should see a line with the following:
127.0.0.1 localhost localhost.localdomain
or
::1 localhost localhost.localdomain
To make the local hostname resolvable, add it to the end of this line. For example:
127.0.0.1 localhost localhost.localdomain john-pc
Once added, if you restart the local license manager, you should be able to start MATLAB. If the license manager is not running locally contact your network administrator for assistance with ensuring that the license server machine is resolvable.
