Ceased Working After Last Update

I have the same issue as this post: https://wordpress.org/support/topic/not-working-after-last-update-4/

Plugin is installed and current version.
Both allow_url_fopen option is enabled and php-curl extension is installed and active.
There are no plugin conflicts. (Deactivated other plugins one by one, no change)

Rolled back to version 1.3.0 and still no change.

There is no section in the post editor for the video thumbnail.
There are no thumbnails uploaded to the server.
Had to deactivate plugin because one has to ‘click’ twice for the video to start.

Please investigate.