Don't have a clue what LightFace is but as the message states "If the problem persists contact Alibre Customer Support and provide the following information:"
Have you done that? Seems like the logical thing to do.
Selecting a face that belongs to a surface body or an open body in a function that expects a solid body (fillet, chamfer, shell, extrude to face, hole on a face).
Selecting on imported geometry (STEP, IGES, SAT) where the topology was not properly stitched into a solid.
Accessing a component in an assembly context whose geometry is only held in memory in a reduced form.
A call from an add-on or AlibreScript that accesses Face through AlibreX and queries the body property. In that case the error would not come from the core application but from third-party code.
A damaged or inconsistent feature tree in which a reference points to a face that no longer exists.
Moving something and deleting it afterwards, which leaves a gap and a reference to geometry that no longer exists. This covers three cases: reordering a feature in the tree, moving geometry in space, and moving a component within an assembly. In each case the stored face reference can outlive the geometry it points to.