500 error

Hello,  I'm receiving a 500 error when i click on the download pdf button,  details say "The website encountered an error while retrieving http://webtest/pdftk-php/pdftk-php/example/download.php?id=1. It may be down for maintenance or configured incorrectly."  Everything else is working great.  Can you help with what i'm doing wrong?

Thanks,

rick
