One more time. I've noticed folks still having a hard time embedding videos.
It's pretty easy to embed youtube and other videos the old fashion way by using the share link.
Go to the video page that you want to embed (we'll use youtube as an example), Click the "Share" link below the video, then click the "Embed" link, then click the "copy" link (that will copy the embed code to your browser), then right click and "paste" the code into the essay or comment body and you're done.
If you want to center the code in the page, highlight all of the code you just embedded and then click the "C" button in the icons above the box (c99text editor) and that will center your video. The "C" button or icon is short for "center".
Almost all the different video sites will have a "Share" or "Embed" link somewhere, you may have to search a bit but it's there.
This FAQ in Method 3 explains it as well.
I had previously recommended using the "Video URL" box below the c99 text editor but I had forgotten that it only allows one video at a time to be posted, my bad.
Mastering the share links on the various video sites will allow you to embed almost all videos on the web. It's also how you embed twitter tweets as well.
I hope to eventually fix the video filter so as to get the video icon working again. There was a major conflict between the c99 software and the video filter code that was causing severe problems site-wide.
Sorry about the inconvenience and thanks for your patience.