Dan, that’s not the Dropbox share link for that file. Dropbox share links will look like this: https://www.dropbox.com/s/zsjd9ayf570jxru/Electric%20Circuit%20Components%20and%20Configurations%20Sample.mp4?dl=0
Notice the ‘/s/’ after http://www.dropbox.com – that means it’s a share link.
You have to use the share button on Dropbox to share a file. I think you did the right-click and copy link– that don’t work.