Error 4753: Hidden Paragraphs - Help Authoring Site
The Warning relates to a paragraph that has the font attributes of hidden. Normally EasyHelp/Web removes these for you but in some cases it cannot do so.
First thing... don't worry it is *only* a Warning message and the Help compiler simply ignores the hidden paragraph marker.
If you do want to get rid of the message use the standard Word Find command to search for paragraph marks (^p in English) that are hidden. Make sure you have the paragraph marks showing before you do the search.