Game Center Problem with SimCity BuildIt

My city, Bethany, has disappeared from the game. I reloaded the app and the City does not show up. The game started me with a new city. The LOG In to Game Center tab has appeared but the log in fails… Message: 

"Hello Mayor!

Could not retrieve data form the server for this Game Center account.

Please try again.

(Error code: 1200.0.999 - Player ID 1880405259.”

 I am using an iPad and the GameCenter to store the game.