Unable to reproduce:
- Created octagonal shape in Maya
- exported to fbx in directory 4 folders deep from desktop (see image)
- Opened project copied to C:/ UE4 (see image)
- imported fbx from test directory
- changed octagonal significantly by extruding a face and re-texture mapping
- re-imported fbx successfully from test directory with changes
I have seen a number of reports from people having issues with importing fbx files from Blender into other programs besides UE4. Please verify your export steps by comparing them to those in this video: [Blender to Unreal Engine 4 in a Nutshell - YouTube][2]