2D animtions

I’m trying to make an archer shoot using a model and animation from the asset store. However, Unity continuously gives me these two errors:

Default clip could not be found in attached animations list.

The AnimationClip ‘Archer3_Attack1’ used by the Animation component ‘Archer 1’ must be marked as Legacy.
UnityEditor.DockArea:OnGUI()

What does this mean?

Check this answer:

Regards

So, in the upper right corner of your animation window in inspector.

Press this little button here:

Set this to Debug.

Toggle animation type between 1 and 2 to get desired needs. In your case I believe the legacy setting is 1.