The module content_rss_creator does not check if an xml folder exists before trying to save inside inside it. There is also no feedback whether the saving was successful.
Implement a check to create xml folder if folder does not exist. Check if saving was ok and if so (and only if) output a message "Created RSS" or the like.
Steps to reproduce:
Install example client
Go to Content -> Articles -> System Pages -> RSS Creator
Make changes and save