title: Jupyter Notebook upgrade made everything disappear
body: <p>I have been using Jupyter Notebook and Python for a while and I had a plenty of notebooks. Today I upgraded Jupyter Notebook (<code>pip install --upgrade notebook</code>) and suddenly everything disappeared. </p>
  
  <p>The console window says to copy the token in the browser, but after I paste it and run it, the webpage is still blank and nothing happens.</p>
  
  <p>Operation system is Windows 7 and on my computer I have installed three different versions of python: 2.7, 3.4, 3.6 and also Pycharm and Anaconda is installed. Previously I have been using the Jupyter Notebook with the 2.7 version of Python.</p>
  
  <p>I am working on an assignment project for my school. I don't even understand how can a simple upgrade install mess things up.</p>
  
  <p>I am by no means an expert in Jupyter Notebook so I'd like to learn how to handle this. Please see attached the images of the blank Jupyter Notebook webpage and the console.</p>
  
  <p>This is the blank webpage:</p>
  
  <p><a href="https://i.stack.imgur.com/UMj4T.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/UMj4T.png" alt="enter image description here"></a></p>
  
  <p>And this is the console:</p>
  
  <p><a href="https://i.stack.imgur.com/75ELO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/75ELO.png" alt="enter image description here"></a></p>