My walls have sections missing

not sure it goes in this section.
but i was in the process of making a house and out of the blue parts of my walls have vanished and nothing i do will fix it. is there something that i did that messed it up?

has there been any similar issues?

Hi Ave

What materials are you using?

Are these created out of BSP, Static meshes made in UE4 or imported Meshes??

With the materials, can you show the details panel?

they are BSP made in UE4

This is happening to me as well. I will make some BSP walls and sections will disappear as if there is a subtraction brush there, but there isn’t. I can’t seem to recreate the problem, it just happens randomly.