Tell us which versions you are using:
"react": "16.3.1",
"react-native": "0.55.2",
"react-native-router-flux": "^4.0.0-beta.27",
undefined is not an object (evaluating 'resetAction.actions.map')
Change to "react-native-router-flux": "4.0.0-beta.27" (remove ^) otherwise your package manager will still install the .28 version (unless you have a .lock at .27)
Related to #2799
I believe this is not fixed in 4.0.6. I have problems with the REPLACE.
Most helpful comment
Change to
"react-native-router-flux": "4.0.0-beta.27"(remove^) otherwise your package manager will still install the.28version (unless you have a.lockat.27)