I was flying from Oslo to Bergen with my friend and as we continue our flight i seemed to notice a wall in the scenery, so did my friend i was flying with, he also saw the wall. After our flight I double checked and cleared scenery cache if it would do anything, and as I spawned the wall was still there.
Hello! This is because we do not have the terrain data for this very small part of the world. This blog post explains it all in detail. Thanks!