Reasons for "Failed to lookup views (...) in directory (...)" error?

Hey I'm trying to debug an error that's comming up with rendering a .jade page with node.js and ExpressJS.

The error is: Error: Failed to lookup view "/workspace/friends" in views directory "C:\Users\Utilizador\Documents\GitHub\QuantBull-Project\views".

So what are the reasons for occurring this error. I'm asking this because supposedly it should be working fine, at least it does with the other files...

I created a the following GET listener, located at controller/workspace.js to render the file:

 /**
   * GET /workspace/friends
   */

  app.get('/workspace/friends', function (req, res) {
    res.render('/workspace/friends', {
      url: '/workspace'
    });
  });

and the file called friends.jade is located under views/workspace.

So I was wondering what can originate this error? Because this situation looks different compared to the other situations with the same error message I found on SO and others...