Trouble previewing a Node.js application on Workspaces

I'm currently going through the "Build a dynamic site with Node.js" course. Following the instructions step by step, I have no problem running the server on node and previewing the results returned by the app. Of course, when I make a request to "https://teamtreehouse.com/myusername", I receive a warning that the user has been moved permanently.

I am aware that treehouse has now moved the API to https, so I go ahead and change every http method to https (keeping http for status codes). The problem is, the preview then doesn't display the results requested, but a warning:

"Workspace Unavailable This is a preview link for a Treehouse Workspace that is not currently active. If you are the workspace owner, you can launch it again via the Treehouse site."

Here's a snapshot of my code (it's basically the code provided for by Andrew, with the changes to the http methods: https://w.trhou.se/265ai7uns5

I don't know if I'm doing something wrong, or if maybe the exercise is now outdated?Anyway, it's quite frustrating, I try to keep going with the course but it's hard without being able to see the results of my work!

Any advice? Thanks a lot!