This issue has been asked earlier at here
This was accepted answer given by Mathworks support team
``This problem has been known to occur when the license file has been corrupted. If you are experiencing this error message, please make sure that your license file is in the correct format (see page 2-3 of the 'Installation Guide for UNIX').
This error may also be caused by mounting the installation disc without the setting the executable bit for the file system. MATLAB?". ''