I added the php

hi guys, I added the php code suggested in a previous help ticket so I could add my on videos to the Integrated Video Tutorial page. I uploaded my mp4 file and test played it and all was good. A few days later I came back and now when I click the video it says it is corrupted. I can play it on my desktop fine and have uploaded a new version yet it still says it is corrupted. Can you help please? I have given you access to the site that has the issue.
Thanks