Animator blend tree not animating

I'm working on 2D sprite movement animations and I'm having some trouble getting my blend tree to play the animation. It plays in the preview, but when I run the game, my sprite will change to the first frame of the Up/down/right/whatever animation but then not play the rest.

It's also not allowing me check the Mirror Animation box to flip my Right Walking animation to use for Left Walking.

Thanks for any insight you guys have here.