MATLAB: Do I receive License Manager Error 400

I recently had a  trial and have now purchased and installed a license.
When I start MATLAB I am prompted to log in and then get the following error:
 
License Manager Error 400
License checkout failed.
License Manager Error 400
The license you requested has expired.
 
How can I resolve this error?

Best Answer

This error indicates that your MATLAB installation was not properly converted from the trial to your new license.
The issue can be resolved by removing the XML file that MATLAB uses to determine whether it should prompt you to log in.
The file is located in a folder named "R20XXx_licenses", where "R20XXx" is the release of MATLAB (e.g. R2015a).
 
Windows:
C:\Users\%USERNAME%\AppData\Roaming\MathWorks\MATLAB\R20XXx_licenses\license_info.xml
 
Linux / Mac:
~/.matlab/R20XXx_licenses/license_info.xml
To find the folder on a Mac:
- Open Finder
- On the Apple menu bar, click on "Go"
- Select "Go to Folder"
- In the text box, enter the following:
~/.matlab
- Click on "Go"