Game-Breaking Glitch?!?!

You heard me right. A game-breaking glitch. I hadnt downloaded an update for this for a month or so, and then boom. I randomly get on and find that my progress has been completely reset and I have gone from level 23 to level 1! It reset all progress on my device for no reason and it said things about Game Center. It had never previously prompted me to sign in before, so why does it do so now that my progress is gone?

Kinkykitty9000 about Bloons Monkey City, v1.11.1