Express 3 error middleware not being called

Question

I am trying to setup error handling for my express app and running into the following problem.

I defined an error middleware and add it as the last middleware:

Answer 1

EDIT 2 (sabtioagoIT) works. But just for those who missed it, emostar's solution also works. I understood to move the error handling 'use' call to the end, but there seems to be an easier option as emoster suggests, use app.router (before the error handling 'use' call).