Optimization solving issue

Hello, 

The california mock grid works fine until the problem solving part. When I run the optimization problem there's the following error: 

ValueError: Cannot broadcast dimensions (8760,) (8760,1)

I have seen this error when working on cvxpy examples and that's why I have already downgraded to Python 3.6 from 3.7. 

I am not sure what to do now. 