Would be gratefull if someone could tell/lead me thru this how to fix it.
Thanks in advance. 
Have a nice day
Hmm all I can see is a little thumbnail, clicking on it does nothing, unless it’s something on my end.
We need more information 
-do you use bsp brushes?
-is that the default material?
-have you already built the light?
-set your quality settings to “epic”
I used BSP
Yes it is default
Light is build
Where have you imported the mesh? Do you receive any errors when importing?
When importing, try recalculating normals and tangents to see if it makes a difference.
It could be that this is caused by the bug which happens when you use bsp brushes + build the light -> try it again with the 4.7.4 version
thank you for help it helped case closed