SSL-Protocol missing in this Image -URL
(template-Mod) :
https://anymod.com/mod/youtube-banner-modal-lllamb
this original line should be requested via SSL - it is called like this:
src="http://i3.ytimg.com/vi/{{ videoId }}/hqdefault.jpg"
should be changed to SSL :
src="httpS://i3.ytimg.com/vi/{{ videoId }}/hqdefault.jpg"