title: Pycharm unresolved reference in virtualenv
body: <p>When I started a new project in Pycharm using virtual environment, I got an unresolved reference warning message.</p>
  
  <p><a href="https://i.stack.imgur.com/nAFL6.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/nAFL6.png" alt="enter image description here"></a> </p>
  
  <p>But I have installed django to my virtual environment and this code is working  correctly. </p>
  
  <p>How can I fix this? I'm using PyCharm 4.5.2 Pro</p>