I am currently open a bunch of city but when I try to take them they always in peace mode, but yet my enemies are claiming those buildings and I cannot. When they take the buildings I am still unable to take from them. I don not understand why? I am done open city like crazy for my enemies and not allowed to claim them for myself. I am on Eternal Fury PDT server: EF Server 276 My game name is : Accalia

If you are referring to castles, only officers can capture. But if it's normal cities, maybe you're attacking a city that has a defense troop, or your guild already has the max amount of cities.