The message "Language string failed to load: invalid_address: You must provide at least one recipient email address." is because you have file integrity checking enabled in jomDefender and you don't have an admin email address defined (probably?) and there's also an issue with your Joomla installations language file set up. Essentially there's an error displaying the error message for a different error. I recommend setting an administrator email so that you can be warned of integrity checks failing or disabling integrity checking (since if it does find anything, you won't be notified if you don't have an email defined).