Getting Workspace Unavailable instead of JS error message: Build a Simple Dynamic Site with Node.js

events.js:141                                                                                                            
      throw er; // Unhandled 'error' event                                                                               
      ^                                                                                                                  

Error: write after end                                                                                                   
    at ServerResponse.OutgoingMessage.write (_http                                                                       
    at Object.view (/home/treehouse/workspace/rend                                                                       
    at Profile.<anonymous> (/home/treehouse/worksp                                                                       
    at emitOne (events.js:77:13)                                                                                         
    at Profile.emit (events.js:169:7)                                                                                    
    at IncomingMessage.<anonymous> (/home/treehous                                                                       
    at emitNone (events.js:72:20)                                                                                        
    at IncomingMessage.emit (events.js:166:7)                                                                            
    at endReadableNT (_stream_readable.js:905:12)                                                                        
    at nextTickCallbackWith2Args (node.js:442:9)  

var Profile = require("./profile.js");
var renderer = require("./renderer.js");

//Handle the HTTP route GET / and POST / i.e. Home
function home(request, response) {
  //If url == "/" && GET
  if(request.url === "/") {
    //show search
    response.writeHead(200, {'Content-Type': 'text/plain'});
    renderer.view("header", {}, response);
    renderer.view("search", {}, response);
    renderer.view("footer", {}, response);
    response.end();
  }
  //If url == "" && POST
    //redirect to /:username
}

//Handle HTTP route GET / :username i.e. /chalkers
function user(request, response) {
  //if url== "/...."
  var username = request.url.replace("/", "");
  if(username.length > 0) {
    response.writeHead(200, {'Content-Type': 'text/plain'});
    renderer.view("header", {}, response);

    //get json from treehouse
    var studentProfile = new Profile(username);
    //on "end"
    studentProfile.on("end", function(profileJSON) {
      //show profile

      //Store the values which we need
      var values = {
        avatarUrl: profileJSON.gravatar_url,
        username: profileJSON.profile_name,
        badges: profileJSON.badges.length,
        javacriptPoints: profileJSON.points.JavaScript
      }
      //Simple response
      renderer.view("profile", values, response);
      renderer.view("footer", {}, response);
      response.end();
    });

    //on "error" 
    studentProfile.on("error", function(error) {
      //show error
      renderer.view("error", {errorMessage: error.message}, response);
      renderer.view("search", {}, response);
      renderer.view("footer", {}, response);
      response.end();
    });

  }
}

module.exports.home = home;
module.exports.user = user;