Diagonal Lightning Relfection

Hey Guys,
First of all, i’m new with ue4. I tried to build a room but everytime i use a lamp, i get these diagonal reflections:

http://puu.sh/mvK48/b35de0fe77.jpg

I dont know why these reflections occure… Not just with this lamps, same with spotlights and other ones…
The settings are just the standard settings (i’m new, so I’m not really into the settings) and the material nodes are these:

http://puu.sh/myVwS/f147df42ce.jpg

Thank you for your answer in advantage,
:slight_smile:

Closing as a duplicate of: Lightning buggs? - Rendering - Epic Developer Community Forums