Why do I receive MathWorks Licensing Error 7?

Why do I receive the following error:

MathWorks Licensing Error 7

or 

License Manager Error -7

A licensing error occurred while trying to use <PRODUCTNAME>.

Unable to communicate with your organization's license server.

Answer 1

[MathWorks Support Team]

Please refer to the MATLAB Answer below for more information.

Why do I receive "MLM: No socket connection to license server manager. (-7,10015)"?

https://www.mathworks.com/matlabcentral/answers/216384