The two most common causes of License Manager Error -9 are:
The MATLAB license file was activated for a different computer and/or user account You have a Designated Computer MATLAB license and MATLAB is already running under a different user account on this computer MATLAB was activated for a different Computer and/or User Account More specifically, this means that the host ID specified in the license file is not the host ID of the computer. If you are using an Individual license, this may also indicate that the login name specified in the license file does not match the logged-in user account.
To resolve this issue, you need to reactivate MATLAB using the correct host ID/Username:
What is a Host ID? How do I find my Host ID in order to activate my license? https://www.mathworks.com/matlabcentral/answers/101892
How do I find my Login Name in order to activate my license? https://www.mathworks.com/matlabcentral/answers/96800
If reactivating does not resolve the license manager error -9, and you are using a Designated Computer license, another user might already be using the license under a different account:
MATLAB is running on a different user account The Designated Computer license option only allows one account on a computer to run MATLAB at a time. If you are using a Designated Computer license and have already confirmed that your host ID is correct, then there is probably an instance of MATLAB running under a different user account on this machine.
To test this, log out any other users on this machine. Be sure to check with your colleague to make sure that none of them have unsaved worked open on those other accounts before logging them out.
