Cannot export BSP Geometry

Hello,

Using UE4 4.24.3, I cannot seem to select all my brushes, and Export Selected, as I keep getting:

“The selection has nothing that can be exported to fbx”

I am slected a single bursh in the outlined, then using CTRL+SHIFT+A to select all the other brushes. Also, I tried selecting all the brushes in the outliner with the same results.