If you have a Wordpress website and if you was previously using the FREE edition of the Screen Reader plugin, you may experiment issue once installed the full paid version. Replacing the free version won't work!!!
Indeed to ensure that the full paid version is installed correctly, you have to completely uninstall the previous free version and clear the Wordpress/browser cache.
After that you can perform a clean upload/install of the full paid version to be sure that it's installed correctly and all scripts are refreshed.