This error occurs when attempting to open an instance of MATLAB configured to use Login Named User with a MathWorks Account that is not linked with this type of license. This means that you are logged in to the local domain account of the person licensed to use MATLAB, but using a MathWorks Account that is not linked to a Login Named User license. This issue is not related to the MathWorks account credentials used to log in, rather the way the license is configured.
If you have multiple MathWorks Accounts, please try using a different set of login credentials, or verify that you have a Login Named User type license under your License Center online. You can access the license center from the following link, and use the Licenses drop down in the top left hand side of the screen to toggle between Licenses and Trials, Prereleases, and Betas:
https://www.mathworks.com/licensecenter/
If you do not have a Login Named User type license under your MathWorks Account, then you can use the activate button in the error to activate your normal license on this computer. If you do not have a license under your MathWorks Account, then you will either need to purchase one or request a trial using the following link:
https://www.mathworks.com/programs/trials/trial_request.html
