When I update to 0.43.0 - rc. 1 version
npm WARN react-native@0.43.0-rc.1 requires a peer of react@~16.0.0-alpha.3 but none was installed.
npm install -save react@~16.0.0-alpha.3
To solve the problem

@droidwolf, where can I find the newest version of react and react-native such as react@~16.0.0-alpha.3 and react-native@0.43.0-rc.1 , I only can find 0.42.3

https://github.com/facebook/react-native/releases

+1

I got that error as well on react ^15.4.2 and react-native 0.43, but upgrading to 16.0.0-alpha.6 fixed it. So id say.. stay away from 0.43 or use react 16.0.0-alpha.6

Seems that RN 0.43 shouldn't made it out of the door in this stage, particularly when essential Components like ListView got deprecated as 0.43 is not ready for serious usage yet.

I was also having trouble upgrading. I decided to start a brand new project and migrate things over as a last resort.

I get @droidwolf's error on init of a brand new project, not changing a single thing.

I'm on the latest version of MacOS and Xcode. What else am I missing?

EDIT: I restarted the simulator (not the packager, but the simulator) and everything seems to work now. sigh

This is a library issue, restarting xcode, cleaning your build, clearing npm cache and running react-native run-ios fixes the issue. Not sure which one ... I really hate node libraries sometimes.

"react": "16.0.0-alpha.6", this version got me working