There are two ways to connect to engine, with or without an app:
- if you want to connect with an app you need to fill in the app id in the field where you have written 'Test'
- if you want to connect without an app, just leave the field empty. You can then use the 'Scenario get applist' to get the list of apps, where you can find the app id of your app
I don't know exactly why you get this strange error, but it might be because the appid is used for load balancing also, and the load balancer fails to find an engine for a non-existing app.
Hope this helps!