[Plugin:Simple Video Embedder WordPress plugin] Not working

Hello All,

I am using on demand theme by press 75 and two plugins by them:

http://www.press75.com/the-simple-video-embedder-wordpress-plugin/

and http://www.press75.com/documentation-support/simple-post-thumbnails-setup-usage/

But both plugins are not working.. nothing is showing.. any idea?