If you have a Facebook page listed in the "Social Media Sources" area of your Juicer dashboard (along the left-hand toolbar), visit your Connected Social Accounts page, and connect a personal Facebook page that has administrative powers for the Facebook page you are displaying in the feed.
For example, if you are displaying the Facebook page @YourBusiness in your Juicer feed, and John Doe is an admin for that page, simply visit the Connected Social Accounts page, and add John Doe's Facebook profile by clicking the orange chain icon:
Once you have established that connection, the video posts in your Juicer feed should function properly again, although it may require waiting until your next scheduled refresh (which will depend on your plan level). No posts from John Doe's Facebook page would be displayed within the feed. This connection just helps Juicer obtain the posts on your behalf.