title: PyCharm SetUp existing env
body: <p>I've updated existing win app to newer version 2019.3.1.</p>
  
  <p>Now I'm not able to use project specific virtual environments.
  When I'm open with Ctrl + Alt + S the Settings menue and take a look at Project Interpreter it use nothing. And I'm not able define the settings to use project specific env.</p>
  
  <p>When I'm add a Python interpreter and choose "New envrionment" pycharm tell me that the path is not empty. That is right. When I choose "Existing environment", e.g. C:\Users\xxx\Desktop\python\robotics1\venv, I'm not able to click on the "OK" button.</p>
  
  <p>Any idea?
  Thanks in advance
  Andreas</p>