We are currently investigating an ongoing issue where Facebook posts are failing and we're receiving an error from Facebook stating "Please reduce the amount of data you’re asking for, then retry your request".
This is an API bug that has been logged with Facebook over here:
https://developers.facebook.com/support/bugs/448867966487671/One thing to note is that even though you may receive this error message, it does appear some posts are still being successfully published to Facebook - so it would be good to check if your post is live, despite the error message.
We will continue to monitor this situation and we will update this incident accordingly when we have more information to share.