The Need
I was working on a project at work, being it was a React project and needing a datepicker, it was time to try the MaterialUI Datepicker.
Installing the packages
Following the documentation at material-ui my dependencies looked like this.
Copying and pasting the example in:

Fail Whale
I was greeted with the following result:

The Googling
Like all good developers I began to google and found a Github issue that matched my problem. The solution was to use an earlier version of the @date-io/date-fns library since a new 2.0.0 version had just come out 4 days prior and @material-ui had issues with it, being it was newer than the last release of material.
Downgrading
So I downgraded to the earlier version and this was the dependencies I ended up with:

Success
Finally after choosing the earlier version I was successful.

** Sometimes newer isn't always better **

Top comments (1)
Faced the same issue and solved it the same way few days back. Looks like we walked through the same path.