I have this problem that my sub-level aint showing ingame. In The editor it is visable and when The game is loading the sub-level is loaded… So i have no idea whats wrong? Hope some of you know this problem and how to fix it 
i am using the play button in the editor for the testing.
How to fix: right click on the level and under “assign to layer” select the “uncategorized” 
Hi Jonas, glad to hear your issue was resolved.
Remember there is an official documentation about making landscape with the dev kit here :
https://sites.google.com/a/studiowildcard.com/ark-dev-kit-documentation/environments/level-design