I've successfully uploaded a couple of videos in the past, so it's not like I haven't figured out how to do this.  But now, when I want to upload a video and I click on the "Select files from your computer" button, nothing happens.  The YouTube page remains the same and I don't get the opportunity to select any files.  I get the feeling there's a simple solution to this issue, and I'm going to feel like an idiot when I find out what the problem is.  As such, I've hesitated five days before asking this question.  Now that I have not figured it out, I ask you:  What am I missing here?