When exactly is advanced placement unlocked?

[Daze90 0]

I read a manual I downloaded from the official site, and it said advanced placement unlocks when your city has reached a certain level. But I just don't get it. Sometimes, when I start a new city, it's already unlocked. Sometimes it isn't.

So I'm kind of wondering why it's like that.

[Buzzy 0]

When in-game, click the little box in the upper left of your screen ("Main Menu") then in the dropped menu click the wrench ("Menu") and in the little menu you get you should be able to click "Toggle Individual Buildings/Zones", that should do it. If not, check in your options if you are playing in Expert Mode (In the main menu).

They changed it in a patch recently, i'm not even sure if you need a certain number of population anymore.