This error could be caused by a number of things.
1. This error can occur on a client machine when the hostname in the SERVER line of your license.dat file does not match the hostname on the SERVER line of your license server's license.dat file. The client machine's SERVER line must match that of the license server. Contact your License Administrator to confirm the hostname in the SERVER line.
The license file on the client machine varies depending upon operating system and version. For R2008a and above, the license file is generally called network.lic and is located in $MATLAB\licenses (where $MATLAB is the MATLAB installation directory). For versions prior to R2008a, the license file will generally be the following:
Windows
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$MATLAB\bin\win32\license.dat (for 32-bit MATLAB)
$MATLAB\bin\win64\license.dat (for 64-bit MATLAB)
Linux/Unix/Mac
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$MATLAB/etc/license.dat
2. This error can also occur if the hostname of your license server is not resolvable. To test this, run the following command from a terminal/command prompt:
ping <hostname>
where <hostname> is the hostname of the license server as it appears on the SERVER line of your license.dat file.
If the output of the above command comes back as 'unreachable' or 'unresolvable', then please contact your System Administrator and have them address this issue.
