maxitems not displaying the correct number

I set maxitems to 9 and it doesn’t always display 9. I think it is because the js for the youtube api is not being loaded correctly and it is causing the script to get interrupted. In the Chrome console I am getting 404 for http://mydomain.com/player_api?ver=3.9.1 I looked through the code but couldn’t resolve the issue.

https://wordpress.org/plugins/youtube-channel-gallery/