Why do I receive the error "LoginWidget :: No endpoint specified" when trying to sign into MATLAB?

Why do I keep encountering the error "LoginWidget :: No endpoint specified" when trying to sign into MATLAB or the Add-Ons Explorer?

Answer 1

[MathWorks Support Team]

This issue may be due to a problem with the Service Host required for MATLAB. Please try uninstalling and reinstalling the Service Host to see if the issue persists. This is different from reinstalling MATLAB itself; MATLAB does not need to be uninstalled in order to uninstall and reinstall the Service Host. 

For instructions on uninstalling/reinstalling the Service Host, please see the following MATLAB Answer:

How do I uninstall and reinstall MathWorks Service Host?

https://www.mathworks.com/matlabcentral/answers/1815365