I was tweaking the mate panel trying to solve some other problem, when I changed the panel settings, from GNOME2, to something else. all my panel apps disappeared. Suspicious of that happening, I clicked the save button, before hand, but now I don't know how to restore my panel apps, there is no button for that.
From Zanna's comment, it would appear I am missing a feature of Mate Tweak. I don't see the panel option anywhere. This might be why I cannot restore my save. http://imgur.com/a/3VyWr