title: Selenium-Firefox: Firefox browser crashes when running my Selenium script
body: <p>I was running some scripts I had developed in Selenium-Python today. They were working just fine. When I closed out a window &amp; went to re-run a test, the Firefox browser that opened up would crash &amp; my script would fail. This literally happened one second to the next. I wasn't sure what had changed to cause this.</p>
  
  <p>I'm running Selenium 2.53 &amp; Firefox 47 on my machine. Occasionally when I try to run my script again, I will get this run error in Pycharm:</p>
  
  <p>File "C:\Python34\lib\site-packages\selenium\webdriver\firefox\firefox_binary.py", line 98, in _wait_until_connectable
      raise WebDriverException("The browser appears to have exited "
  selenium.common.exceptions.WebDriverException: Message: The browser appears to have exited before we could connect. If you specified a log_file in the FirefoxBinary constructor, check it for details.</p>
  
  <p>Normally I just get an error when I manually close the crashed FireFox browser that opens. Any ideas as to what occurred?</p>