Hello again.

I am having a problem splitting a part in half using a parting surface in SolidWorks.

The goal is to split a hollow solid object into two distinct pieces, an upper and lower piece. The cut itself is rather complex, a pattern that runs around the outer surface of the solid object. Unlike the previous thread with the same name, this particular object has parting lines that perfectly overlap object features, and this seems to prevent the split operation from functioning correctly.

To illustrate I created a very simple demonstration.

1. I created a hollow box via extrusion of a 2D sketch.
2. I added two more extrusions to make a "ceiling" and "floor" to the box.
3. I sketched a 2D pattern on the four outer walls of the box and applied "Split Line" to them. Note that the lines are colinear to the inner ceiling and floor of the box.
4. I used the "Parting Surface" tool and selected all the edges created by the previous split lines.
5. I finally attempt the "Split" feature using the generated parting surface but it fails to split the object in two.

If no ideal solution if available, a work-around might be to offset the parting lines some small distance from the ceiling and floor of the box. I'd like to avoid doing that if I could help it.

Attached is my project file. Any help would be appreciated! Thank you.