Merchant of Venice can't buy a City State

I have a Merchant of Venice, I have moved next to a city state, but the only option I'm given is a trade mission. It has trade mission bonuses, but I'd really like a puppet. I've seen a video where the Merchant has an action icon that looks like a trade mission, but has a gold coin on top of it, but I only see the Mission/Move/Do Nothing/Sleep/Embark/extra actions, and the only extra is delete the unit.
The city state is allied and under protection of Greece, but I haven't read about that as a restriction.
Other Venice stuff is working - 2*trade routes, free Merchant, trade mission bonus, and no settlers allowed.
I've never played Venice before, so I'm not sure if there a rule I'm missing or if it is a bug.
I am playing Steam version BNW on a Mac - in case that makes any difference.
Best Answer
The game was set to One City Challenge, but I had not set it to One City Challenge. I know because I restarted another game being careful to do no special options (just Venice), but it still ran a One City Challenge Game.
A previous player had gone into a sub-sub menu (Advanced Setup >> Advanced Game Options) in Set Up Game, and set to One City Challenge. When I did subsequent games with Set Up Game, it kept all of the previous settings, including all the 'hidden' Advanced Game Options.
It seems like a fairly major option to keep persistent in a sub-sub menu! I would consider this a UI bug.
Pictures about "Merchant of Venice can't buy a City State"



Can Venice buy city-states?
Due to the fact that the Merchant of Venice is a Great Person, it is possible, although unlikely, for it to be gifted to a player who is not currently playing as Venice, as long as they have all of the Patronage policies adopted. In this case, its ability to buy city-states remains intact.Can Venice capture cities?
Venice. You can never build or capture settlers. You can never annex conquered cities.How do you stop Merchant of Venice Civ 5?
Can you free a city state in Civ 5?
In vanilla Civilization V, liberating a city is possible only if the city was part of an extinct civilization or city-state. In order to "liberate" a city originally belonging to an existing civilization, it would have to be puppeted or annexed and then gifted to its original owner.The Merchant of Venice 2004 720p BluRay
More answers regarding merchant of Venice can't buy a City State
Answer 2
You have to be allies with the city state in order to buy them out. You must remain allies with the city state for 10 turns or you can't buy them
Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.
Images: Andre Moura, Enric Cruz López, Ekrulila, Russell Butcher