It is not possible to live stream your videos to Facebook and other platforms ( currently YouTube and Periscope) at the same time. Facebook prohibits any third party, using their live steam API, to live stream the same video to any other destination at the same time. So when selecting multiple social accounts to live stream your video, you cannot select Facebook social accounts together with YouTube and/or Periscope. However you can select multiple Facebook social accounts OR select multiple YouTube and Periscope accounts.
The following table summarizes all possible social account combinations
If you want to broadcast a video to Facebook and other social accounts at the same time you must upload the same video twice and set the same scheduling time both times. In this way your video will go live on Facebook and other social accounts at the same time.