on the index.php page, since you use require once to include the ssi/ch-ssi-nav-fmEd--starterPage.php:
<?php require_once("ssi/ch-ssi-nav-fmEd--starterPage.php"); ?>
that causes the ssi/ch-ssi-nav-fmEd--starterPage.php page to inherit the location of the index page
So this line:
<?php require_once( "../webassist/security_assist/helper_php.php" ); ?>
needs to be changes to:
<?php require_once( "webassist/security_assist/helper_php.php" ); ?>