A customer sent me a Dropbox link to a video file. The link works fine, and the video is viewable with no problems. At the bottom of the screen is a message saying, "Keep it save in Dropbox. Quickly find it from any device by saving it to your own Dropbox folder."
However, when I try to sign in, although I can put in my user name and password, when I click on the "Sign in" button, it grays out the "Sign in" button, but otherwise it does absolutely nothing. It just sits there.