Indefinite "Loading" Under Video on Post After Plugin Activation

Hello,

I’ve installed the YouTube Comments plugin and have generated my API key and credentials and updated them in the app settings. Now, when I view my posts where I have YouTube videos embedded, underneath the video, I presume where the comments should be loading, all I get is an indefinite ‘loading’ box. I’ve tried both this plugin and the Slava fix plugin. Both are giving me the same results.

Can you please advise?

Thank you.

Link: http://www.lordkayoss.com/2015/09/18/metal-gear-solid-v-s-rank-fast-easy-episode-1-phantom-limbs/

https://wordpress.org/plugins/youtube-comments/