If MATLAB fails to start with an error like "License checkout failed" or "Invalid license file," consider the following checks:
The file named license.lic (or simply license.license or license.dat in some installations) is a text license file that MATLAB and MathWorks products use to validate and configure network (floating) or standalone licenses. It contains license server definitions, feature names, expiration dates, host IDs, and cryptographic signatures that the MATLAB license manager (FlexNet/flexlm) reads when starting MATLAB or the license server. license.lic matlab
If you open a license.lic file in Notepad (which you can do), you will see lines of code looking something like this: If MATLAB fails to start with an error
SERVER license-server.mycompany.com 123456789abc
USE_SERVER
INCREMENT MATLAB MLM 123 31-dec-2024 1 ...
INCREMENT Simulink MLM 123 31-dec-2024 1 ...