QT Question With Yosemite

JUST UPLOADED TO YOSEMITE. PROBLEM WITH QT DEALING WITH SAFARI

I belong to site called Actors' Access. When I submit my photo and resume, I have the opportunity to include a video clip, which Actors Access uploads, not me. I just went to include my video clip for a submission. I wanted to preview it, which I can do via Actors' Access. What I get is a Q with a question mark in it. I pressed open window. Nothing happens. All the other clips open and play, but not this latest clip. Yes, I did call Actors Access, figuring it was something to do with their upload, but it plays fine on their computer. I also went to Firefox, I can play it on Firefox AFTER I got a dialogue box that said activate QT... it's Safari, I'm having this problem with. How can I get this video clip to play on Safari, with Yosemite as my operating system. Is there a way to activate QT, as Firefox asked me to do? Thanks for any help solution. Peter