This error occurs when trying to activate a license/trial (e.g. Login Named User Trial) that does not allow activations.
During an install for a Login Named User trial, a license_info.xml file will get created in the user profile for the user performing the install. If the installation was performed under a different user account (e.g. account with Admin rights) then the license_info.xml file, which is required by MATLAB, will only be found by MATLAB when logged into the computer as that user.
To fix this installation:
1. Download the attached license_info.xml from the link below this Answer (Note, if your browser opens the file instead of downloading it, please download the .zip file instead and extract the license_info.xml from it).
2. Place license_info.xml into {matlabroot}/licenses (where {matlabroot} is your MATLAB installation directory):
C:\Program Files\MATLAB\R20XXx\licenses (Windows)
/usr/local/MATLAB/R20XXx/licenses (Linux)
/Applications/MATLAB_R20XXx.app/licenses (macOS) (Right click on the MATLAB application and click show package contents to open the MATLAB_R20XXx.app folder.)
3. Start MATLAB. You should now be prompted to provide your MathWorks Account login information to access your trial.
Alternatively, the "-licmode online" startup flag can be used to start MATLAB in LNU mode without the need for an xml file. To launch MATLAB with a startup flag, open a command prompt/terminal window and enter the path to the MATLAB executable and the “-licmode online” flag.
Windows:
"$MATLAB\bin\win64\MATLAB.exe" -licmode online
Linux or Mac:
./matlab -licmode online
