Looks like Rhino is having a bit of difficulty splitting the complex object… What I would do is first duplicate the edge of the odd-shaped “window” hole in Right view, temporarily hide the big rectangular block and then trim the complex polysurface with the duplicated curve. Then show the rectangular block, and Split the block with the trimmed polysurfaces. From the split result, delete all but the main block, then select the imner polysurface and the block and Join.
Here is the result…
CutSolid.3dm (3.4 MB)
Boolean operations are combined intersect/split/delete/join operations, so if they fail, it’s a good idea to try manually and see where they fail. Then try to figure out a way to either fix or work around it.