Quadtree: object reference not set to an instance of an object

I take faces of the walls on which I run sunlight analysis, have points with values of sunlight hours received then I proceed to culling the point density depending on their values and plug all that in to quadree to get the structure, its in branches with original planes. Works well with other parts of the building that I have done all tho they have been on the same plane but different heights. But this time around I get the error object reference not set to an instance of an object, on the inspection of the component you can see that it has produced a few structures out of many. What is going on?