[After installing] undefined is not a function

[philohelp]

I get this message and I have no idea where to look for...

[paomosca]

this is related to new version of react-navigation that requires listener for windows events like focus and blur.
to solve easily the issue you can refer to this: react-navigation-mobx-helpers

this boilerplate is very old now, i've not so much time to maintain the code updated