title: Webdriver Exception:Process unexpectedly closed with status: 1
body: <p>I try to run a selenium program on a Linux machine.But I got the exceptions:</p>
  
  <pre><code>    Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
    File "/usr/lib/python2.7/site-packages/selenium/webdriver/firefox/webdriver.py", line 154, in __init__
      keep_alive=True)
    File "/usr/lib/python2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 151, in __init__
      self.start_session(desired_capabilities, browser_profile)
    File "/usr/lib/python2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 240, in start_session
      response = self.execute(Command.NEW_SESSION, parameters)
       File "/usr/lib/python2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 308, in execute
      self.error_handler.check_response(response)
    File "/usr/lib/python2.7/site-packages/selenium/webdriver/remote/errorhandler.py", line 194, in check_response
      raise exception_class(message, screen, stacktrace)
  selenium.common.exceptions.WebDriverException: Message: Process unexpectedly closed with status: 1
  </code></pre>
  
  <p>How can I fix the exceptions? Thanks for helping.</p>