These tools cannot fetch included files ( #include virtual="..." ). They only view the base file.

An .shtml file is a standard HTML document that contains Server Side Includes (SSI) directives.

To help refine this architecture for your project, let me know: What you are using (Apache, Nginx, IIS)? The approximate scale of your website (How many pages)?

You view SHTML properly by double‑clicking the file locally — your browser would show raw SSI code instead of the merged output. To see the final rendered page, you must serve the file through a web server that processes SSI.

Turn on error messages during development to see exactly why an include is failing to view, but turn them off or make them silent in production to prevent exposing your server's directory structure to public users. To help find the right setup for your project, let me know: What operating system are you developing on? What is your preferred code editor ? Share public link

Check the file paths inside your tags. Ensure they are relative to the server root or the current file path.