"Use self" doesn't work? I'm currently working with drivers in Blender 2.81 and want to use self but it doesn't work. 

For example drive the rotation by the location, I'm adding a driver to the rotation, check the Use Self box and write self.location.x

Blender return the message: ERROR Invalid Python expression.

Have I missed something, is it a bug?

edit:
I'm working on 2.9. Problem is still here.
Allowing auto run python scripts fixed it.