I've been asked to fix a broken breadcrumb, but never worked with SSI shtml, so please bear with me.
They are trying to call a js function from within shtml that is being called by another shtml.
<!--#include virtual /shtml/abreadcrumb.shtml"-->
<script src="script/location/abreadcrumb.js">
<script>
callabreadcrumb();
</script>
the js has been working until it was dropped into shtml, so I am not tinkering with it.
You have to close the first script tag:
<script src="script/location/abreadcrumb.js"></script>
<script>
callabreadcrumb();
</script>