Cannot import name 'tf_utils' when using importing keras

I had the same problem, but upgraded Tensorflow via pip rather than downgrading Keras and this solved the problem :)

Using Python 3.6.4, Keras 2.3.1, Tensorflow 2.0

Seems like it was a problem with keras 2.3.0, I installed keras 2.1.5 using pip and it works fine.