Play with your Miis first before updating the plaza

I had to learn the hard way at the bookstore that updating your Mii Plaza before you play with your Miis won’t let you play with them afterwards because it all resets. So ten Miis I had lost. They were still in my plaza of course but it wouldn’t let me play with them anymore. Better luck the next day. They are doing 10 days of National Streetpassing.