i have test in24, but dont think thats the issue, the issue you have some perimeter curves there are very short and then fail…and be sure you have so many slopes as curves…btw you could try test manuelly with revit ui and if it fail there as well, then the node dont wanna help as well
I see. Yes, I tested it manually with the revit interface and it works without any problems. It’s strange because the script doesn’t give any problems anyway … 
However, you are right, I tried it in the same buildings you tested it on and it works :D. However, is there a way to just select all the top faces automatically without having to click them one by one manually?
yes select element-get element faces- get the surface normal- get vector z- get vector z 1…and filter you faces with filter by bool mask and you should have the topsurface
Thank you very much. It works! 
Is there any way to fix the geometry of generic models? That would be great!
yeah but probably not a solution there will work in every situation
Good morning! Could you tell me the possible solution to solve the geometries you mentioned last time? It is very important for me to be able to do these roofs. Thank you
yeah as mention it will probably be building by building…but guess the original question have an answer…so try create a new topic with that and we can probably find a solution on that as well but i dont think its a way there works in all situation
Ok, thank you