title: Anaconda Navigator does not start on Linux Mint
body: <p>Installed Anaconda on Linux Mint 19 as per the instructions. After installing I try to start the Anaconda Navigator via "anaconda-navigator".</p>
  
  <p>It does not start and I get the error:</p>
  
  <p>"UnboundLocalError: local variable "DISTRO_NAME" referenced before assignment</p>
  
  <p>Any ideas how to solve this?</p>
  
  <p>Many thanks</p>