Can't move the mouse in The Witness

I got Reshade to load in The Witness but the mouse doesn't move (okay, it's moves a little) so I can't configure Reshade. I tried running in lower resolutions and switching between fullscreen and windowed but the mouse won't budge. Does anyone know of a workaround?

It happens to me too in some games. The mouse gets stuck in the middle of the screen. I pause the game and can move the mouse. Though it is annoying if the game has pause screen which means you cannot see your changes.