When I click to configure IIS, it takes me to this URL: wp-admin/options-general.php?page=hide_my_wp&die_message=iis but says this on the page: The page cannot be displayed because an internal server error has occurred.
As you have mentioned that when you click to configure IIS, there’s internal server error issue. Can you please check your server error log for the detailed error message regarding this? And are you getting this error in only this page or any other pages too?
Configure IIS page should list the rules that you should add to your site’s Web.config file. Can you please try updating PHP version to 5.6+ and increase the PHP memory limit? You might need to ask Hosting provider regarding these. If it’s still the issue then please apply for the refund from your Envato panel. Thanks!