Good day, magickaldragon. I hope that you are having a great day. I also appreciate the excellent opportunity to be of assistance via this channel.
As a consumer, I know how important it is to get those pictures via MMS. We need to isolate the issue further to explore resolution options.
You mention that Facebook pictures shared with you via message are black. Are other pictures (not Facebook pictures) coming to your phone correctly when shared via Message+?
What happens if you take a picture with your phone and send it via Message+ to your own number? Does it come to your phone correctly?