title: Rselenium remDR$open() error
body: <p>I am running this code:</p>
  
  <pre><code>devtools::install_github("ropensci/RSelenium")
  require(RSelenium)
  RSelenium::checkForServer(update=T)
  RSelenium::startServer()
  remDr &lt;- remoteDriver()
  remDr$open()
  </code></pre>
  
  <p>And getting this error:</p>
  
  <pre><code>[1] "Connecting to remote server"
  Error:   Summary: UnknownError
       Detail: An unknown server-side error occurred while processing the command.
       class: org.openqa.selenium.WebDriverException
  </code></pre>
  
  <p>And despite searching (honest!), I can't find out why this is happening. Any help anyone could offer would be greatly appreciated. </p>
  
  <p>Thanks!</p>