title: finding out what is causing dreaded "The website encountered an unexpected error. Please try again later." message
body: <p><br>
  while doing a drupal 6 to 7 upgrade I am getting the not so helpful message
  "The website encountered an unexpected error. Please try again later." everytime I go to certain pages.
  ex) /admin/config</p>
  
  <p>What is the best way to find out what is causing the fatal error so that I can fix it?  </p>
  
  <p>All I can think of right now is to start disabling contributed modules until that page works or looking through the logs.</p>
  
  <p>Thanks.</p>