How to build

[Motowater]

I think I'm doing something wrong, but I'm blaming it on the game.

For example, I will have researched a water mill, but cant build it even though the specific upgrade is researched and I'm on a river, does not let me build it. And it seems this way for half the science and civics I've upgraded. It's just not letting me build them. I feel like I'm playing a "basic" version of the game.

Another example is I build a theater square which was upgraded, but I cant build an amphitheater after it. (Screenshots)

I must be doing something wrong. Any advice?

 

[criZp]

In that picture angkor wat already has an amphitheatre, it's visible on the map.

When you have built a building it will no longer be visible in the production menu, as opposed to the districts, which stay visible with the brown frame around.

 

[Motowater]

That explained it, Thanks.