title: Unity: Cannot add property to animation
body: <p>In the Unity editor I cannot add any property to an animation. I'm trying this by double clicking the highlighted element "Scale". <br><br>
  (Note: the "Add Property" button is active, not greyed out, see the image)</p>
  
  <p><a href="https://i.stack.imgur.com/5yafv.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/5yafv.png" alt="Trying to add the property"></a></p>