This issue appears when trying to silently install a Support Package using the workflow from this URL.
How do I silently install Support Packages for MATLAB R2018a or newer?
There is a known issue that you are currently unable to silently install Support Packages for MATLAB if the Support Package Root folder already exists. In order to silently install a support package, you need to delete the Support Package Root folder and allow the silent installation process to create the folder. This means you are currently unable to silently install Support Packages if there is already a Support Package installed for your installation of MATLAB.
You can confirm the Support Package Root folder by running the following command:
If you can use a GUI, you can also install Support Packages using the offline workflow instead.
How do I install a Support Package on an offline machine?