Hi Ming,
I understand that you are receiving an error message after installing MATLAB. You are right, the error message hints that you are logged in as admin user instead of your computer username. As per my understanding, the License Manager Error-9 occurs predominantly because the MATLAB license file was activated for a different computer and/or user account. This means that the Host ID specified in the license file is not the Host ID of the computer.
You need to reactivate MATLAB using the correct Host ID or Username to address the error. You can leverage Finding my Host ID and Activating my License threads for following the correct procedures.
For in detail information on changing your username, you can visit the following pages depending upon your operating system Windows - OS-X - Ubutnu
I hope this helps.
