Xbox 360 controller not being recognized?

[Billiard26]

"xinput/0/gamepad" is your 360 controller.
'When I select the gamepad option, the "Device" field goes blank' is a known bug. Just map your controls normally after choosing the device.
'And the "Main Stick" and "C stick" boxes with the graphics in them, do not update' sounds like you didn't map your controls.
Show a screenshot if you still have issues.