I ran into the same issue as SQSBMedia. When I accessed my website I was getting an error re an unexpected ‘{‘ – expecting ‘(‘ on line 2.
I think the solution is a missing set of brackets in the functions.php code after get_child_extensions. It should be:
<?php
function get_child_header_extentions() {
require_once( get_stylesheet_directory(). '/child-header-extensions.php' );
}
?>
This worked for me – at least until I try to modify child-header-extensions.php file.