Formik and Yup : TypeError: Cannot read property 'object' of undefined

I had the same problem and then I realised I was using yup in the code instead of Yup. Below is the code sample and it works perfectly :)

import * as Yup from "yup";

const formSchema = Yup.object().shape({
  email: Yup.string().required().email(),
  password: Yup.string().required().min(6),
});

The correct answer is not to downgrade, but to change how you import it.

Try import * as Yup from 'yup' instead of import Yup from 'yup'.

// wrong
import Yup from 'yup';

// correct
import * as Yup from 'yup';

Here is your example working: https://codesandbox.io/s/xlnw2x0kk4.