Well, there's not much to show, because the stool will be invisible in the before shot, but of course I'd be happy to share some screenshots anyway. :-)
Here's a link to an imgur album showing off the stool in Skingrad's Rosethorn Hall before and after the mesh fix: imgur.com/a/jgKL9ZN
Hi, katkat74!
I hope it is acceptable to write in English. I couldn't find anything about it in the site rules.
I love your beautiful furniture replacer, but I found that one of the items, the small stool, "upperstool01.nif", turns invisible at certain angles, and I can also no longer activate it to sit on it.
However, I managed to find a way to solve it; it seems the problem is that the centre coordinates of the mesh are incorrect.
Open upperstool01.nif in NifSkope, navigate to 0 NiNode -> 7 NiTriShape -> 12 NiTriShapeData, right click it, and in the menu that appears select Mesh -> Update Center/Radius, and then save the mesh.
I hope someone will find this information useful. I am by no means a NifSkope expert, so it's possible that there are better solutions, but this method solved it for me, and I can now sit on your pretty stools. :-)