On our new site, to add a video, you don't use the youtube "Embed code"or "Share This" code to add videos.
When you click the "+" to add a video, (Youtube in this example) --it asks you for the video's "ID or URL" ....it means exactly that.
So for your YT vid in your post, you can either paste in your video's URL from your browser: (looks like:https:// www.youtube. com/watch?v= G_BSxXwUCLc)..(i added some spaces to break up the link here)
the video's Youtube ID , meaning simply: G_BSxXwUCLc
I believe it works the same way for Vimeo videos.
Those irritated by grain of sand best avoid beach.
-Strumelia proverb c.1990