Using Scala with Sling

https://cwiki.apache.org/SLING/using-scala-with-sling.html

it works fine after a couple days of struggling.
The reason It not working based on above URL steps.
1. You have to install all bundles (about 4) and demos (2 bundles, forum and helloworld) with (1 dependent bundle) before run the demo.

2. If you forum is not working. Read this: The form application is the available at http://localhost:8888/content/forum.html?sling:authRequestLogin=true. When prompted for credentials use admin/admin (you have to login as "admin", "admin" first for posting.