BuddyPress.org

If you’re going to use embed code, you have to make sure that (a) you’ve switched the editor to HTML (rather than Visual) mode, and (b) that you’ve added embed and object to your allowedtags array, either through a plugin that allows such code or through a custom function.

Using the oEmbed method (where you just paste the URL on its own line of the editor) is a far easier solution!