Light problem (New user)

[FlawlessHappiness]

Hello.

I am pretty new in 'this' forum, but i got Amnesia the Dark Descent and discovered that there is a level editor.

I've been making levels in Portal 2 and i actually got pretty good at it, and it hit me that the editor looks quite the same as Anmesia's.
I watched different basic videos and read the tutorial on frictional games. The tutorial wasn't very detailed,
so instead i watched more videos.

I came to the lighting of a room, and according to the videos i can put a light in the room, make sure the lit-button is checked, and the put a pointlight above it. But when i turn of the light in my room (in the editor) the room is fully dark. There is no sphere of light. What do i do wrong?

I've searched on this forum but couldn't find any help...

EDIT: Non-steam