Since the migration to WP 3.8, this plugin no longer works. Here is how the problem is manifesting...
1. The lightbox isn't even appearing; i.e., there used to be a frame which would zoom in to size and dim the page background. Now the thing being displayed just appears in a page with no lightbox, no [X] close icon, no (+) enlarge icon.
2. In Vimeo, private videos are no longer working. This is because no matter what you do, WP Video lightbox is simply linking to the Vimeo site and attempting to display the video there. Since those videos are set to ONLY display at the domain where the plugin resides, it all breaks.
This is a great little plugin; I hope that the author fixes these problems and quickly!