This year the button assignments are now located in an array instead of a cluster. The first section in this webpage (
http://wpilib.screenstepslive.com/s/...e-2014-to-2015), Joystick Get, shows the change for 2015, and the button array begins at 0 instead of 1.
You can change the button assignments by just changing the index you're looking at in the array.