I'm having the same problem running the android emulation as the following guy in this link.
Scanning folders for symlinks in /Users/jloi/dev/lndr-mobile/node_modules (10ms)
JS server already running.
Building and installing the app on the device (cd android && ./gradlew installDebug)...
File /Users/jloi/.android/repositories.cfg could not be loaded.
FAILURE: Build failed with an exception.
* What went wrong:
A problem occurred configuring project ':app'.
> Could not resolve all dependencies for configuration ':app:_debugApk'.
> A problem occurred configuring project ':urbanairship-react-native'.
> Could not resolve all dependencies for configuration ':urbanairship-react-native:_debugPublishCopy'.
> Could not find any version that matches com.facebook.react:react-native:[0.40,).
Versions that do not match:
+ 12 more
Please advise. Thanks.