Hii Emily,
you seem to have accidentally switched your Rotation to Quaternion. What is more, you set all 4 values to 0…that is an ‘illegal’ Quaternion Rotation.
For simple Rotations like this, it is not recommended to use Quaternions.
(For more information on Quaternions, see: https://blog.cgcookie.com/what-are-quaternion-rotations-in-blender/ ,
But you absolutely do not need to know what they are for this Course!)
