title: Selenium WebDriver throws org.openqa.selenium.remote.UnreachableBrowserException while running test cases in parallel using testNG
body: <p>While running test cases in parallel using TestNG "UnreachableBrowserException" is throwing whereas if parallel="false" is given test cases are executing succesfully.</p>
  
  <p>TestNG Version: 6.9.10
  Selenium Java: 3.0.1
  Chrome Version: 58.0.3029.110
  Chrome Driver Version: 2.29</p>
  
  <p>TestNG XML:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd"&gt;
  &lt;suite name="Suite" parallel="classes" thread-count="2" verbose="5"&gt;
    &lt;test name="Test"&gt;
      &lt;classes&gt;
        &lt;class name="testscripts.LoginScenario.ParallelTwo"/&gt;
        &lt;class name="testscripts.LoginScenario.ParallelOne"/&gt;
      &lt;/classes&gt;
    &lt;/test&gt; &lt;!-- Test --&gt;
  &lt;/suite&gt; &lt;!-- Suite --&gt;
  </code></pre>
  
  <p><strong>TESTNG FAILURE EXCEPTION</strong></p>
  
  <pre><code>org.openqa.selenium.remote.UnreachableBrowserException: Could not start a new session. Possible causes are invalid address of the remote server or browser start-up failure.
  Build info: version: '3.0.1', revision: '1969d75', time: '2016-10-18 09:49:13 -0700'
  System info: host: 'A5***-**-00**', ip: '10.43.***.**', os.name: 'Windows 7', os.arch: 'x86', os.version: '6.1', java.version: '1.8.0_131'
  Driver info: driver.version: ChromeDriver
  </code></pre>
  
  <p><strong>CONSOLE</strong></p>
  
  <pre><code>TestNG 6.9.10 by Cédric Beust (cedric@beust.com)
  
  FAILED: mail
  org.openqa.selenium.remote.UnreachableBrowserException: Could not start a new session. Possible causes are invalid address of the remote server or browser start-up failure.
  Build info: version: '3.0.1', revision: '1969d75', time: '2016-10-18 09:49:13 -0700'
  
  FAILED: google
  org.openqa.selenium.remote.UnreachableBrowserException: Could not start a new session. Possible causes are invalid address of the remote server or browser start-up failure.
  Build info: version: '3.0.1', revision: '1969d75', time: '2016-10-18 09:49:13 -0700'
  System info: host: 'A5DA', ip: '10.**.***.**', os.name: 'Windows 7', os.arch: 'x86', os.version: '6.1', java.version: '1.8.0_131'
  </code></pre>
  
  <p>Please clarify!!</p>
  
  <p>Thanks in advance.</p>