[Solved I think...] Sprite Animation Question

Hello UnityAnswers,

I've just started working on the animations for my game, but I'm having a few problems.

Until now, I've been using static Sprites that change according to movement to show the character's facing. Now that I've started trying to use animations, I've received several errors. Most of these I've figured out, but one persists.

I've got a Sprite that I've added Rigidbody2D, BoxCollider2D, Animation and Custom Script Components to my character. The Rigidbody just stops the character from moving through walls on my 2D map. The collider is the same. The Custom Script controls movement and the animation states. The Animator is a bit of a mystery because even though I reference the component, I can't get it to play my animation.

The errors:

1. "The AnimationClip 'walkDown' used by the Animation component 'hero' must be marked as Legacy."

2. "Default clip could not be found in attatched animations list."

I can't figure out how to get my sprite animation to be marked as legacy, and although it says there's no default animation, I have verified that there is an animation set in the animation component.

Any help is much appreciated. Thanks.

P.S. I've looked at all of the Scripting reference documentation.