I am trying to subtract one solid from another(it is a section of handrail), I am trying to remove a section, so I swept a length of the same size and also larger sized handrail along the same path, but when I attempt to subtract the section I wish to remove I get an ERROR: inconsistent face-body relationship. Has anyone found a counter to fix this error and subtract the desired section?AutoCad3D 2013

Sounds like a case of some bad geometry.  I would go back and redo it.