title: JSC profiler is not supported
body: <p>I have some trouble to run my project on iphone device.</p>
  
  <p>it works fine on simulator, but when I test on device which version is <code>iOS9.2</code>, some info output in Xcode console</p>
  
  <pre><code>2016-02-25 19:31:19.357 [info][tid:com.facebook.React.JavaScript][RCTJSCProfiler.m:63] JSC profiler is not supported.
  </code></pre>
  
  <p>then wait a litter longer, red screen appearing that prompt me <code>Could not connect to development server</code>.</p>
  
  <p>What should I do?</p>
  
  <hr>
  
  <p>In addition, I post this question on <a href="https://github.com/facebook/react-native/issues/6146" rel="nofollow">github issue</a> and be told that it's another reason cause crash.</p>
  
  <p>I review my project but also have no idea, simply explain that I integrate a component which inherit <code>UICollectionView</code> written by <strong>swift</strong>, I'll show some main code below.</p>
  
  <p><strong>CollectionViewManagerSwift.swift</strong></p>
  
  <pre><code>@objc(CollectionViewManagerSwift)
  
  
  class CollectionViewManagerSwift : RCTViewManager, UICollectionViewDataSource, UICollectionViewDelegate {
  
    let contentCellIdentifier = "CellIdentifier"
    var collectionView: UICollectionView
  
    override init() {
      let layout = CustomCollectionViewLayout()
      let collectionView = UICollectionView(frame: UIScreen.mainScreen().bounds, collectionViewLayout: layout)
      collectionView.registerClass(CustomCell.self, forCellWithReuseIdentifier: contentCellIdentifier)
      collectionView.directionalLockEnabled = true
      collectionView.backgroundColor = UIColor.whiteColor()
      self.collectionView = collectionView
    }
  
    override func view() -&gt; UICollectionView! {
      self.collectionView.delegate = self
      self.collectionView.dataSource = self
      return self.collectionView;
    }
  
  func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -&gt; UICollectionViewCell {
  
      let cell : CustomCell = collectionView .dequeueReusableCellWithReuseIdentifier(contentCellIdentifier, forIndexPath: indexPath) as! CustomCell
  
      // ... some code describe cell component 
  
      return cell
    }
  
  }
  </code></pre>
  
  <p><strong>CollectionViewManagerBridge.swift</strong></p>
  
  <pre><code>#import "RCTView.h"
  #import "RCTViewManager.h"
  
  
  @interface RCT_EXTERN_MODULE(CollectionViewManagerSwift, RCTViewManager)
  
  @end
  </code></pre>
  
  <p>I also have <strong>CustomCollectionViewLayout.swift</strong> and <strong>CustomCell.swift</strong> which be used in above code.</p>
  
  <p>finally I call this component from js side.</p>
  
  <p><strong>CollectionView.js</strong></p>
  
  <pre><code>import React from 'react-native';
  var { requireNativeComponent } = React;
  module.exports = requireNativeComponent('CollectionViewManagerSwift', null)
  </code></pre>
  
  <p><strong>index.ios.js</strong></p>
  
  <pre><code>import CollectionViewManagerSwift from './CollectionView';
  
  // ... some code
  
  render() {
      return (
        &lt;CollectionViewManagerSwift style={[styles.container, {top:20}]} /&gt;
      )
  }
  </code></pre>
  
  <p>and these code work fine on simulator, I could see my component from swift code which be integrated now,
  I don't know what happened when I test them on iphone device.</p>