This occurs if you have a program called 'VJoy' installed. It will need to be fully uninstalled from your Control Panel/Programs and Features menu.
We're also investigating other third party programs causing this conflict but VJoy looks to be the most commonly reported.
Please check that you only have a keyboard, mouse, and supported controller plugged into your USB ports. If you have multiple devices connected, the game may improperly detect multiple inputs resulting in this issue.