title: Pycharm: "unresolved reference" error on the IDE when opening a working project
body: <p><strong>Intro</strong></p>
  
  <p>I have a Python project on a git repository. Everything works ok for most of the team members, we can sync the code and edit it without any problem with Pycharm on different platforms (Windows, Linux)</p>
  
  <p><strong>The problem</strong></p>
  
  <p>On one of the computers we are getting "Unresolved reference" all over the code on almost every import with the exception of Python's built in libraries (i.e. import datetime is working). This computer is running the Mac version of Pycharm.</p>
  
  <p><strong>The question</strong></p>
  
  <p>Anyone knows how to solve this?, since most of the imports are not recognized code completion and navigation trough goto->declaration and so on is not working. Is there any known issue with the Mac version?</p>
  
  <p>Thanks in advance!</p>