If the server-side include calls a file that is located in another directory
in the account, you need to make some modifications.
For example:
<!--#include virtual="../menu.html" -->
The file named "menu.html" is located in the directory
above the location of the file referencing it.
Instead of using "#include
file" you must use the command "#include virtual".
<body> <!--#include virtual="../menu.html" --> </body>