title: Selenium WebDriver 3.4.0 + geckodriver 0.18.0 + Firefox ?? - which combination works?
body: <p>I'm running Selenium 2.x with Firefox 47.0.2 on Windows Server 2008R2 using .Net.  I'm running x64 code.</p>
  
  <p>I'm trying to upgrade to Selenium 3.40 + geckdriver 0.18.0 but I can't find a version of Firefox that runs 100%.  I'm using x64 en-US versions of Firefox unless otherwise noted.  They were downloaded from <a href="https://ftp.mozilla.org/pub/firefox/releases/" rel="noreferrer">here</a>.</p>
  
  <p>Here's what I have found:</p>
  
  <ul>
  <li>Firefox 51.0.1 - too old - Geckodriver complains "Unable to find a matching set of capabilities"</li>
  <li>Firefox 52.0.2 - I get an IndexOutOfBoundException when calling setPageLoadTimeout</li>
  <li>Firefox 52.2.1esr - I get an IndexOutOfBoundException when calling setPageLoadTimeout</li>
  <li>Firefox 53.0.3 - upon exit, the Firefox window stays up, needs to be closed manually</li>
  <li>Firefox 54.0.1 (tried both x64 and X86) - crashes upon exit</li>
  <li>Firefox 55b9 - crashes upon exit</li>
  </ul>
  
  <p>Is there a combination of selenium 3.4.0 + geckodriver + Firefox that works on .Net for you?</p>