Ok som Im making a map and if I use a main map with world streaming I can spawn in and after I run lets say from x= 1000000 to x= 3000000, still in map boundaries, it just makes me fall of the world and i can see it zooming out till is black. this doesnt happen if I dont use world streaming, and if Play directly on the landscape. Help appreciated.
You might have found the limit 
I don’t know where it is but there is one.
I just had to disable the world camera biasing and it stopped, also I seem to be having issues with post proccesing water, when I use the underwater blendables it turns all black.