Thread:User talk:CodeCat/Trouble adding a new label to Module:category tree/topic cat/data/Place names

Hi CodeCat. I tried to Module:category tree/topic cat/data/Place names, but  ended up generating the error message "Lua error in Module:category_tree at line 126: attempt to index field 'name' (a nil value)" in Category:en:Provinces of the Roman Empire, Category:fr:Provinces of the Roman Empire, and Category:la:Provinces of the Roman Empire. I don't understand what I've done wrong; could you explain to me how to fix this, please?