WooCommerce Predictive Search jquery.autocomplete.js is not include at footer or your site.
I think your theme is missing this core WordPress function
wp_footer() function at footer.php file
Without that function ours and many other properly coded plugins cannot work
<?php
/* Always have wp_footer() just before the closing </body>
* tag of your theme, or you will break many plugins, which
* generally use this hook to reference JavaScript files.
*/
wp_footer();
?>
</body>
</html>
Hope that helps you – suresh
