Why can't I watch videos on the web, but I can with Visual Studio?

I am using EasyHtml5Video code in a web page that works fine to play an mp4 video when using Visual Studio while in ‘Start without Debugging’ mode.  But, when I access the same page that resides at a remote host server, all that I see is a dark area where the video should be seen.  The video files are located in the same file as the web page .aspx files, so the files should be accessible.  What am I doing wrong?  Here is the HTML code:
 
<!doctype html>
<html>
<head>
<meta charset="utf-8" />
<title>CR22d</title>
</head>
<body>
<!-- Start EasyHtml5Video.com BODY section -->
<div style="position:relative;width:720px;height:480px;">
 
    <br />
        <p align="center" style="text-align: center">
  &nbs ...