The current popular HTML Editing programs do an excellent job of creating HTML pages. However, getting the relative link function to work in both the editor and 4D requires having everything set up correctly.

4D Configuration
You must have a default HTML folder defined in 4D. 4D by default assigns this as "WebFolder". Do not follow this folder name with a "/" in your default HTML folder setting. All your HTML files must live in this folder, or children folders. This folder becomes your "root" folder for use with the editing program. (Incidentally, as a bonus, this also helps improve the security of your web site.)

Accessing a file by URL.
Assume that your have a file "index.html" at the root level of your "WebFolder". This file will respond to www.yoursite.com/index.html.

Referencing the file in your HTML Editor
The proper syntax in your HTML editor for the file would be "/index.html" Do not include referencing the "WebFolder" in your editor.

If everything is set up properly, you should have no problems.