Uncaught TypeError: _react2.default.createContext is not a function

question is caused by react version, update your react version, it will be ok.

use "npm update react" and ""npm update react-dom""

//before:

"react": "^16.2.0",

"react-dom": "^16.2.0",

 

//after update:

 

"react": "^16.7.0",

"react-dom": "^16.7.0",