I think you right!
if tried to use a texture on the floor of the first persoon example map, and there it worked perfectly fine!
but now i don’t know how to generate a uv map for my meshes…
i have read the documentation from epic, have watch multiple tutorials but i don’t understand why its not working.
i tried to check the “generate lightmap uv” but it doe’tn seem work… 
do you maybe know how I can fix that? 