Cannot run app, connect-mongodb or mongodb problem?

[sernac]

Hello,
I followed the instructions, but cannot seem to get the app to run. I get the following error message:

TypeError: Cannot call method 'isConnected' of undefined
    at Server.isConnected (C:\...\node-express3-mvc-master\node_modules\connect-mongodb\node_modules\mongodb\lib\mongodb\connection\server.js:208:30)
    at new MongoStore (C:\...\node-express3-mvc-master\node_modules\connect-mongodb\lib\connect-mongodb.js:90:21)
    at Function.<anonymous> (C:\...node-express3-mvc-master\bootstrap.js:55:11)

I also tried the workarounds to this problem found in

• mongodb@1.3.5 TypeError: Cannot call method 'isConnected' of undefined: treygriffith/connect-mongodb#76
  but it did not fix the issue.

Hopefully you can help me out. Thanks!