Why does my exported FBX "grow" a face on my object once exported into UnrealEngine4?

I made a cleaning cart in blender using quite a few Boolean modifiers.

Originally I had the same issue within blender, but after just messing around with the object I was able to fix it.

Now once I export the object as an FBX into UE4, it mysteriously “grows” a face over the handle area.

I have exported the cart with just one (1) receptacle and had no issues, but as soon as I shift D the receptacle part to the other side and join all three (3) objects I have this issue.

I have also unwrapped the UV’s multiple times and feel like they are at the most optimized they can be.

You can try applying all transforms. I think sometimes that helps.

I tried that, and had this issue. see photos

For some reason it is literally just one side. And like i stated once i Shift D the object I run into this error.

And I still get the same error once I bring it to UE4.

@cybereality

Check if the face is a quad or triangle, not an Ngon.
An easy check is to: editMode -> editFaces -> Select -> Select by Trait -> Select Faces by Sides -> set “Number of Vertices” to 4 -> set “type” to “Greater Than”
If the face is an Ngon, just knife tool across the elbow of the face (or select two vertices and “connect” them together.

selectSides2.JPG

elbow1.JPG
elbow2.JPG