Need help with modding [Ck2]

I am trying to mod the [Cities of Wonde(https://steamcommunity.com/sharedfiles/filedetails/?id=1892285697) mod for Ck2, specifically the requirements for building a city of wonder, using the linked off-steam version. But when I remove the line

OR = { realm_size = 200 AND = { is_feudal = yes real_tier = emperor ai = no }}

in 99_cow_wonders.txt, the game crashes on clicking the great work button in the province tab.