Appium unable to identify webelements of hybrid android app

Hello Appium Team,

My same script for hybrid app use to run fine on my previous mac ,but since I shifted to new Mackbook pro, The same script now unable to identify the web-elements of the webview page of my app.

Code:
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Set;
import java.util.concurrent.TimeUnit;

import org.openqa.selenium.By;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.remote.DesiredCapabilities;

import io.appium.java_client.android.AndroidDriver;

public class test_app {

AndroidDriver driver;

 @org.junit.Test
	public void Test() throws MalformedURLException, InterruptedException
	{

		//These capabilities will launch the app and navigate to home screen
		DesiredCapabilities cap = new DesiredCapabilities();

		cap.setCapability("app", "/Users/xyz/Downloads/xyz");
		
		cap.setCapability("platformName", "android");
		
		cap.setCapability("deviceName", "Galaxy J2_BQA1"); 
		
		cap.setCapability("platformVersion", "5.1.1"); 
		
	
		cap.setCapability("autoAcceptAlerts", true);
		
		cap.setCapability("newCommandTimeout", "500");
		
		AndroidDriver driver = new AndroidDriver(new URL("http://127.0.0.1:4723/wd/hub"),cap);
		
		driver.manage().timeouts().implicitlyWait(100, TimeUnit.SECONDS);

	    	
	    	//Here we are in the home screen ,This script will tap on the hamburger icon to open side menu
		    driver.findElement(By.className("android.widget.ImageButton")).click();
	    
	    //Locate 'Sign In' button and tap  on it
	    driver.findElement(By.xpath("//android.widget.LinearLayout[1]/android.widget.FrameLayout[1]/android.widget.LinearLayout[1]/android.widget.FrameLayout[1]/android.support.v4.widget.DrawerLayout[1]/android.widget.FrameLayout[1]/android.support.v7.widget.RecyclerView[1]/android.support.v7.widget.LinearLayoutCompat[10]/android.widget.CheckedTextView[1]")).click();
	    
	    Thread.sleep(1500);
	    
		Set<String> ContextNames = driver.getContextHandles();
		for(String contextName : ContextNames)
		{
			System.out.println(contextName);
			
			   if(contextName.contains("WEBVIEW"))
			   {
				   driver.context(contextName);
				   System.out.println(contextName);
			   Thread.sleep(1500);
			
			   }
		}

   
		//Login screen from side menu--->WEBVIEW
		WebElement a= driver.findElement(By.xpath("//android.widget.LinearLayout[1]/android.widget.FrameLayout[1]/android.widget.LinearLayout[1]/android.webkit.WebView[1]/android.webkit.WebView[1]/android.view.View[4]/android.widget.EditText[1]"));
		 a.click();
	


		a.sendKeys("xyz");
		   
							
		WebElement b= driver.findElement(By.xpath("//android.widget.LinearLayout[1]/android.widget.FrameLayout[1]/android.widget.LinearLayout[1]/android.webkit.WebView[1]/android.webkit.WebView[1]/android.view.View[4]/android.widget.EditText[2]"));
		
		b.sendKeys("xyz");
		
		driver.navigate().back();

	    WebElement loginButton = driver.findElement(By.xpath("//android.widget.LinearLayout[1]/android.widget.FrameLayout[1]/android.widget.LinearLayout[1]/android.webkit.WebView[1]/android.webkit.WebView[1]/android.view.View[4]/android.widget.Button[1]"));
	    
	    loginButton.click();
	    
	    Thread.sleep(5000);
	    
	    
	  
	}

}

Eclipse and appium throws 'No such Element found error

Configuration details:
Appium Version:1.5.3ara
Macbook pro