React Native error when start without debug

Question

I have a bug just after application started by command react-native run-android. Error appears when I switch off remote debug. With debugger all works correct.

Objects are not valid as a React child (found: object with keys {$$typeof, type, key, ref, props, _owner, _store}). If you meant to render a collection of children, use an array instead or wrap the object using createFragment(object) from the React add-ons. Check the render method of `View`.
traverseAllChildrenImpl
    traverseAllChildren.js:183
traverseAllChildrenImpl
    traverseAllChildren.js:102
traverseAllChildren
    traverseAllChildren.js:218
instantiateChildren
    ReactChildReconciler.js:86
_reconcilerInstantiateChildren
    ReactMultiChild.js:179
mountChildren
    ReactMultiChild.js:249
initializeChildren
    ReactNativeBaseComponent.js:74
mountComponent
    ReactNativeBaseComponent.js:211
mountComponent
    ReactReconciler.js:61
performInitialMount
    ReactCompositeComponent.js:495
mountComponent
    ReactCompositeComponent.js:346
mountComponent
    ReactReconciler.js:61
performInitialMount
    ReactCompositeComponent.js:495
mountComponent
    ReactCompositeComponent.js:346
mountComponent
    ReactReconciler.js:61
performInitialMount
    ReactCompositeComponent.js:495
mountComponent
    ReactCompositeComponent.js:346
mountComponent
    ReactReconciler.js:61
mountComponentIntoNode
    ReactNativeMount.js:54
perform
    Transaction.js:149
batchedMountComponentIntoNode
    ReactNativeMount.js:77
perform
    Transaction.js:149
batchedUpdates
    ReactDefaultBatchingStrategy.js:65
batchedUpdates
    ReactUpdates.js:111
renderComponent
    ReactNativeMount.js:141
render
    ReactNative.js:31
renderApplication
    renderApplication.js:33
run
    AppRegistry.js:76
runApplication
    AppRegistry.js:105
__callFunction
    MessageQueue.js:236
<unknown>
    MessageQueue.js:108
guard
    MessageQueue.js:46
callFunctionReturnFlushedQueue
    MessageQueue.js:107

versions of libs

"react-dom": "~15.3.2", "react-native": "^0.39.2",

Answer 1

In my case with React Native we dragged this mysterious bug for weeks appearing just on Android builds without an attached debugger as you described

The culprit was an

import 'core-js'

on our root component, it seems the polyfill was messing things up

Just remove the import line and give it a try

Relevant portion of package.json

  "react-native": "0.44.2",
  "react": "16.0.0-alpha.6",