node.js + express error: cannot read property 'url' of undefined

I'm fairly new to Node.js, installing it to try out the DrupalChat (v7dev) module. I believe this problem is with either node.js or express, as I am beyond the stage where the chat module's settings are loaded. I am faced with the following output when trying to start the chat server

Extension loaded: drupalchat_nodejs.server.extension.js
Started http server.
   info  - socket.io started

node.js:201
        throw e; // process.nextTick error, or 'error' event on first tick
              ^
TypeError: Cannot read property 'url' of undefined
    at Function.handle (/usr/local/lib/node_modules/npm/node_modules/express/node_modules/connect/lib/proto.js:105:18)
    at Server.app (/usr/local/lib/node_modules/npm/node_modules/express/node_modules/connect/lib/connect.js:60:31)
    at Server.serverListening (/usr/local/lib/node_modules/npm/node_modules/socket.io/node_modules/policyfile/lib/server.js:136:16)
    at Server.g (events.js:154:14)
    at Server.emit (events.js:64:17)
    at Array.1 (net.js:710:10)
    at EventEmitter._tickCallback (node.js:192:40)

I remember when express installed, it gave a warning like ".... bugs['web'] should probably be bugs['url']" (I can't remember the prefix)

So is it that the server is trying to read an (API?) variable 'url' but its currently 'web'?

I have all the modules up to date, is it that I should downgrade? Or is there some way of working around this using another module?

EDIT: line 201 is the last very line (delete authenticatedClients[authData.authToken];)... I just added to whole function for proper context

var authenticateClientCallback = function (error, response, body) {
  if (error) {
    console.log("Error with authenticate client request:", error);
    return;
  }
  if (response.statusCode == 404) {
    if (settings.debug) {
      console.log('Backend authentication url not found, full response info:', response);
    }
    else {
      console.log('Backend authentication url not found.');
    }
    return;
  }

  var authData = false;
  try {
    authData = JSON.parse(body);
  }
  catch (exception) {
    console.log('Failed to parse authentication message:', exception);
    if (settings.debug) {
      console.log('Failed message string: ' + body);
    }
    return;
  }
  if (!checkServiceKey(authData.serviceKey)) {
    console.log('Invalid service key "', authData.serviceKey, '"');
    return;
  }
  if (authData.nodejsValidAuthToken) {
    if (settings.debug) {
      console.log('Valid login for uid "', authData.uid, '"');
    }
    setupClientConnection(authData.clientId, authData, authData.contentTokens);
    authenticatedClients[authData.authToken] = authData;
  }
  else {
    console.log('Invalid login for uid "', authData.uid, '"');
    delete authenticatedClients[authData.authToken];
  }
}