Q: Game Center

Hi,

I just bought a new iPhone 6Plus, and i've tried to login to game center. I put my Apple ID n password in the game center login, but when i tap the sign in, authentication page come out and ask to put in my password. After i put in the password nothing happened, it goes back to authentication page with blank password. What should i do then, so i can login to game center. Thanx a bunch.