[Crash] Add a landscape with an active light source


I want to design a new small Map for ARK to get more experience with the Dev Kit, but I’m unable to create a new landscape. The whole engine crashes when I create a new landscape (7x7quads, 1x1 section, MI_NewIsland material). If I deactivate the light source, it works perfectly. Do you have any ideas or tricks to solve this problem?

Information of my computer:
i7-6700 CPU 3,40 GHz
GTX 1070