No error handling at all in a "real-world-example-app" is a "no-go"

[TorstenR]

Error handling is essential in any productive app: so why there is nothing implemented herein?
As you can see this sample produce errors (reported within issues), maybe you can at least provide / implement an error handling similar to that sample: https://medium.com/@aleixsuau/error-handling-angular-859d529fa53a