Video Player Block Help

Permalink
I'm having trouble getting the c5 video player block to work. I thought it would be as simple as uploading a video to the file manager and then choosing that video for the block. However, when I do that, nothing shows up. It's usually blank or sometimes the Quicktime image will show up, but that's it. No video. Videos in mov format are supported, right?

Any suggestions would be appreciated. Thanks so much