I've noticed that river tiles no longer give any gold yield. This makes it difficult to have a decent economy and military in the beginning of the game. This is particularly problematic at the King difficulty setting. Was this by design or am I experiencing a bug? I think they're may be a better way of addressing the late game gold surplus balance issue.
River gold was moved elsewhere, but cities now give 1

per city, and the empire itself receives an extra 2

/turn. This means your first city is basically working 3 river tiles right away and each city after that is working 1 river tile. Coastal regions are also better, starting at 2

1

.
This is to equalize the value of river and non-river start locations in the very early game.
After this 2

/empire 1

/city starting gold, there's five ways to increase gold supply:
- Sailing if near a coast.
- The Wheel if near rivers.
- Trapping for trading posts.
- Calendar for most luxuries.
- Archery for camp luxuries.
- Masonry for marble.
@Seek
I found and fixed the problem preventing Republic from giving happiness, thank you.
Still not sure what could be the cause of odd diplomacy events, nothing I do alters diplomacy directly (only general AI tendencies like building large armies or allying with citystates).
Thank you for the help with the research bug. Knowing the display is correct means it must be a problem with the way I'm giving the science, somehow. I patterned it off Afforess's Tech Diffusion, so I know the general principle works, I've just got to find where the bug is.
@Kirschi
Thank you for pointing out the anarchy thing, I've added a check for that.
I found and fixed the bug with the top-left display being off by one turn, thank you.