Licensing error: -15,570. System Error: 115

Hello! I am trying to run Matlab R2016b using my university's license (National Technical University of Athens).

After the installation when I run matlab from matlabroot/R2016b/bin I get this error:

1. MATLAB is selecting SOFTWARE OPENGL rendering.
2. License checkout failed.
3. License Manager Error -15
4. MATLAB is unable to connect to the license server.
5. Check that the license manager has been started, and that the MATLAB client machine can communicate
6. with the license server.
8. Troubleshoot this issue by visiting:
9. http://www.mathworks.com/support/lme/R2016b/15
11. Diagnostic Information:
12. Feature: MATLAB
13. License path: /home/usr/.matlab/R2016b_licenses:/home/usr/Applications/MATLAB/R2016b/licenses/license.dat:/home/
14. usr/Applications/MATLAB/R2016b/licenses/network.lic
15. Licensing error: -15,570#. System Error: 115

What should I do?

[Walter Roberson]

https://www.mathworks.com/matlabcentral/answers/404028-license-problems-cheat-sheet lists a couple of possibilities.