Shadow problem

Hi,

I’m new to Unreal Engine and currently playing around with some tutorials.
At first the shadows in the level look correct. Like it does now in the editor:

So the shadow in the editor worked with the sun in the game as expected.
But suddenly (I’ve must hit some setting without notice…) it stopped working in-game:


Before the sun cast shadows, now it does not and it looks like a redish layer.

Regards.