IPS is no longer able to support the feature due to changes made by Facebook, which now requires a Facebook developer account App (free) for their oEmbed system. You can however restore the embed functionality with this inexpensive plugin, which updates Facebook and Instagram embeds to use the new Facebook App authentication system.
You have to jump through a few hoops, and spend $10, but it's worth the trouble. Once configured with your Facebook App credentials, it's pretty much a 'set it and forget it' plugin. @rebraf will help ensure future compatibility.