Trade routes

On another forum I visit it seems like there are a ton of questions around trade routes and how to properly establish them - so I'll make a thread here. I'm also not convinced there isn't a small bug regarding harbors, but I don't see anything mentioned in the bug forum.

From what I know, building a harbor on a coastal city will immediately establish a trade route with your coastal capital, and your capital does not need a harbor. That's the way it's been working for me. I know a few games ago though I had that scenario and everything was fine, but then in my secondary city I had built a road to a nearby City State after which my trade route went away. Not sure why.

My current question is: how do I connect a city on another continent, and one hex away from the coast??? I built a road to the shoreline thinking that would do it, but no. I can't build a harbor there, and I obviously can't build roads over water.

INCORRECT.

YOUR CAPITOL OR CONNECTED CITY ALSO NEEDS A HARBOR.... which the game conveniently does not mention. I had a game where I had oversea cities. I built harbors in those cities... not connected. I then build a harbor in the capitol... CONNECTED.

So, you need a coastal city... with a harbor. Inland cities are not sufficient.

Zen Blade said:

INCORRECT.

YOUR CAPITOL OR CONNECTED CITY ALSO NEEDS A HARBOR.

Click to expand...

I appreciate the caps and all, but I'm just telling you what I'm seeing, not what the developers intended. I have successfully used harbors in secondary cities while not having a harbor at my capital.

Now in my current game I'm seeing that potential bug again. I have a secondary small continent where my coastal cities (at least two of them) have harbors, yet no trade routes are being established. So then I built one at my coastal capital - still no trade routes. I'll post the save game here.

Am I missing something or is this bugged?