Hi!
I imported 2 amations from mixamo and created a controller, asigned it to the character prefab, but it doesn´t work when I clik play button
I´m suspecting this is happening because the model does not have all the parts of the body or bones specified (rigged), it only has one child called default.
Is it neccesary to have the model rigged before? If so, how can I do it? Do I need an external program?
Mixamo has an auto-rigging system where you specify the bones, and it works there.
Thanks!
Kind regards 
can you post screenshots of your issue what play button you’re clicking etc
Don’t forget to Make the Model’s Rig to “Humanoid”