madlabmg

The plugin author was referencing JS files hosted on github that have been moved. The best thing is to go find these files and bring them local, but the quick and easy fix is to open the main plugin file (/wp-content/plugins/jquery-html5-file-upload/jquery-html5-file-upload.php)

on lines 202, 203, 204 add /js/ to the path — here are the lines:

wp_enqueue_script ( 'tmpl-script', 'http://blueimp.github.com/JavaScript-Templates/tmpl.min.js',array('jquery'),'',true);
	wp_enqueue_script ( 'load-image-script', 'http://blueimp.github.com/JavaScript-Load-Image/load-image.min.js',array('jquery'),'',true);
	wp_enqueue_script ( 'canvas-to-blob-script', 'http://blueimp.github.com/JavaScript-Canvas-to-Blob/canvas-to-blob.min.js',array('jquery'),'',true);

replace them with:

wp_enqueue_script ( 'tmpl-script', 'http://blueimp.github.com/JavaScript-Templates/js/tmpl.min.js',array('jquery'),'',true);
	wp_enqueue_script ( 'load-image-script', 'http://blueimp.github.com/JavaScript-Load-Image/js/load-image.min.js',array('jquery'),'',true);
	wp_enqueue_script ( 'canvas-to-blob-script', 'http://blueimp.github.com/JavaScript-Canvas-to-Blob/js/canvas-to-blob.min.js',array('jquery'),'',true);

this should fix it, at least until the github changes again. the plugin author should be including the JS files in the plugin itself.