We'll create fresh WordPress site with WP Clean Characters installed. You have 20 minutes to test the plugin after that site we'll be deleted.
Copying and pasting content from the web or other documents can insert invalid characters into post content and create invalid RSS feeds. WP Clean Characters fixes this by converting those invalid characters into valid UTF-8 entities when saving a post. A feature is also included to go through your post archive and clean any invalid characters in those as well.