There is no setting or keyboard layout that will render an entire row of keys disabled.
Consider checking the keyboard by pairing it with other device that you have access to such as another Mac, Windows PC equipped with Bluetooth, an iPhone/iPod or an iPad.
If the behaviour reoccurs, than most likely the keyboard is kaput. If the keyboard is still covered under original warranty or the accompanying Mac is covered under original warranty or Apple Care, you can get it inspected or replaced at an Apple Store or authorised Apple service centre.