I already re-installed onto a new server. I was only testing .. If I do reproduce I will make sure to provide stacktrace. I do appreciate you looking into this. I will make sure in the future that I can provide more details.
As it currently stands, category is hard coded into NodeBB. It will require a lot of work to make the paths custom, but it is a planned feature. So, you will either have to just not change the path or get somebody to change all of the hard coded areas that need to be notified in the site code.