Can't select room, floor/ceiling disappear

[bbergner]

This isn't an island room, it has connections to exterior walls. And I should clarify about the floor and ceiling. They don't actually disappear. The floor COVERING disappears. The slab is still shown. As for the ceiling, that all goes away I think, all I see is the plywood floor from the room above. The strange thing is, when I delete a wall partition, adjoining this room and and adjacent room, the problem goes away. When I replace the interior wall to split the two rooms again, the problem returns. This interior wall partition is between straight, parallel walls and there is positive connection between them.