title: Jupyter Lab - launches but don't see any tabs (look/feel is 100% different than seen in youtube videos)
body: <p>I have <code>jupyter notebook</code> version <code>4.2</code> on my <code>MacOS</code> (10.9.5)</p>
  
  <p>I launch via <code>jupyter lab</code> at the MacOS terminal and it automatically opens a browser at the following link: <code>http://localhost:8888/lab</code></p>
  
  <p>At this point I see the <code>Welcome to the JupyterLab Alpha preview</code> screen but nothing more. No tabs etc. Please see the image I have included. </p>
  
  <p>I am using <code>Chromium</code> (<code>Version 43.0.2357.130 (64-bit)</code>
  ). When I try to open in <code>Safari</code> browser absolutely nothing loads. Its a blank browser session. </p>
  
  <p>What I see in the browser doesn't look like anything that I have seen in all of the <code>JupyterLab</code> videos on youtube (<code>PyData 2016 DC</code> for example).</p>
  
  <p>Clearly there is something wrong with the rendering. </p>
  
  <p><a href="https://i.stack.imgur.com/KBpOY.png" rel="noreferrer"><img src="https://i.stack.imgur.com/KBpOY.png" alt="enter image description here"></a></p>
  
  <p><strong>UPDATE</strong>:</p>
  
  <p>Output in the console:</p>
  
  <pre><code>WebSocket connection to 'ws://localhost:8888/terminals/websocket/1' failed: WebSocket is closed before the connection is established.
  http://localhost:8888/api/contents/untitled.txt?1485120059877 Failed to load resource: the server responded with a status of 404 (Not Found)
  http://localhost:8888/api/contents/DeleteMe.ipynb?1485120060078 Failed to load resource: the server responded with a status of 404 (Not Found)
  </code></pre>
  
  <p>Output in the MacOS terminal:</p>
  
  <pre><code>[I 16:20:58.569 LabApp] JupyterLab alpha preview extension loaded from /Users/user1/anaconda/lib/python2.7/site-packages/jupyterlab
  [I 16:20:58.570 LabApp] Serving notebooks from local directory: /Users/user1
  [I 16:20:58.570 LabApp] 0 active kernels 
  [I 16:20:58.570 LabApp] The Jupyter Notebook is running at: http://localhost:8888/
  [I 16:20:58.570 LabApp] Use Control-C to stop this server and shut down all kernels (twice to skip confirmation).
  [W 16:20:59.883 LabApp] No such file or directory: untitled.txt
  [W 16:20:59.884 LabApp] 404 GET /api/contents/untitled.txt?1485120059877 (::1) 3.88ms referer=http://localhost:8888/lab
  [I 16:20:59.893 LabApp] New terminal with specified name: 1
  [W 16:21:00.095 LabApp] No such file or directory: DeleteMe.ipynb
  [W 16:21:00.098 LabApp] 404 GET /api/contents/DeleteMe.ipynb?1485120060078 (::1) 5.14ms referer=http://localhost:8888/lab
  [W 16:22:35.969 LabApp] 404 GET /lab/xterm.js.map (::1) 64.85ms referer=None
  [W 16:25:30.075 LabApp] No such file or directory: untitled.txt
  [W 16:25:30.076 LabApp] 404 GET /api/contents/untitled.txt?1485120330069 (::1) 1.74ms referer=http://localhost:8888/lab
  [W 16:25:30.101 LabApp] 404 GET /lab/xterm.js.map (::1) 3.18ms referer=None
  [W 16:25:30.296 LabApp] No such file or directory: DeleteMe.ipynb
  [W 16:25:30.297 LabApp] 404 GET /api/contents/DeleteMe.ipynb?1485120330283 (::1) 1.73ms referer=http://localhost:8888/lab
  </code></pre>
  
  <p>Output of browser console:</p>
  
  <p><a href="https://i.stack.imgur.com/Ok5zs.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Ok5zs.png" alt="enter image description here"></a></p>
  
  <p>UPDATE:</p>
  
  <p>Here is a specific video of Jupyter Labs I watched:</p>
  
  <p><a href="https://www.youtube.com/watch?v=Ejh0ftSjk6g" rel="noreferrer">JupyterLab: Building Blocks...</a></p>
  
  <p>What I see is very different than what is shown in the video. There are many other videos on youtube.</p>
  
  <p>UPDATE #2:</p>
  
  <p>I followed Feynman27's instructions <a href="https://github.com/jupyterlab/jupyterlab/issues/408" rel="noreferrer">here</a> however I get the same result. See screen shot. I see where it says, <code>Click on the Launcher tab for the initial JupyterLab screen</code>, however I can't find where that is. </p>
  
  <p><a href="https://i.stack.imgur.com/tmWux.png" rel="noreferrer"><img src="https://i.stack.imgur.com/tmWux.png" alt="enter image description here"></a></p>
  
  <p>UPDATE #3:</p>
  
  <p>I updated my browser to <code>Chromium Version 56.0.2924.87 (64-bit)</code>.</p>
  
  <p>Now all works fine. I see the tabs. </p>