I Just got the upload working yesterday, I can tell you this, extract the zip file, and place the resulting folder into your webpage, you can rename it to "upload" or what ever. When you head over to
www.yourpage.com/upload/ .. the default index.html file kicks in and and file uploaded will be placed into /upload/server/php/files/ .. at least that's what happened on my computer. I've tried changing the location of the uploads but it's futile. I'm still trying and I'll let you know once I get it done. When I changed any variables in main.js or the index.php inside /server/php/ I got errors like the above. So you might want to check if the upload works with defaults first before trying to change anything. :)