Re: I cant connect to Sim City Build it

It’s important to note:

• It’s only possible to build your city on one device at one time! If your game account is being played simultaneously on two different devices, you’ll see an error message and will be unable to continue. Close your game on one device to continue playing on another.
• If you’ve been playing on a new device, connecting through a social account will save your progress. 
• If you’ve been playing on a new device, connecting through a social account which already has saved data associated with it will result in the loss of any progress made on that new device. (You’ll see a confirmation message to make sure this isn’t done accidentally.) 
• If you have been playing offline on one device and start to play online on a secondary device (using the same account login), any offline progress you made on the first device will be overwritten and cannot be retrieved.

http://help.ea.com/en/article/saving-game-and-making-social-connections-in-simcity-buildit/