title: WebDriverException : Missing 'type' parameter
body: <p>I am using Selenium Webdriver in python. The environment condition of my setup are -                                                                  </p>
  
  <p>python 2.7.12<br>
  selenium 3.4.2<br>
  Firefox 52.0.2<br>
  Geckodriver v.0.13.0<br>
  on running python script following line of code is giving error  </p>
  
  <pre><code>self.driver.implicitly_wait(30)                                                             
  </code></pre>
  
  <p>Error message is WebDriverException : Missing 'type' parameter.<br>
  Can anyone help me in this situation ?</p>