Viewport/Wrapper not resizing vertically

I am running the Testimonials Widget with the premium version on my site and neither myself nor my developer have been able to sort out some of the bugs that we are having. I am hoping you might be able to provide some insight. The widget isn’t resizing properly to accommodate the content. Vertically, things are being cut off. We’ve fixed the horizontal alignment/sizing issues, but we can’t seem to track down the source of the vertical problems. When I Inspect it in Chrome I am finding an error, “Failed to load resource: the server responded with a status of 406 (Not Acceptable)”. I also find that a lot of the controls for sizing in the widget settings have no effect. (I can’t change the height of the viewport in the settings). Hoping you might have some ideas.

http://wordpress.org/plugins/testimonials-widget/