Salient 8.5.4 is Now Compatible with Woocommerce 3.3.1 . Kindly update the Theme if you have updated Woocommerce . 


Make button open lightbox

The correct HTML to add a button with an icon that links to a video would be:

<a class="nectar_video_lightbox nectar-button small accent-color regular-button magnific-popup" target="_blank" href="" data-color-override="false" data-hover-color-override="false" data-hover-text-color-override="#fff" style="visibility: visible;" rel="prettyPhoto"><span>Test Span</span> </a>