Right Click Glitch

I don't know why but every now and then my right click (which in my game is to use a sword) doesnt work upon entering a layout. i have checked everything, has this happened to anyone else?

actually, have just encountered one where both left and right dont work. this often happens from when i leave my game over screen to go to the level and even more commonly when i leave game over screen too quickly. although, this doesnt happen every time that happens. only every now and then