More info: that tile never had miasma on it.

Trying to load the save with rising tide of miasma did not work. At all. So the mystery remains until I start a vanilla EoE game. I hope I'll be able to find a reliable way to reproduce this before that.

Luckily this is just a minor nuisance. I don't really want to give up using other mods.

Another river tile without farming option next to the same city here.

Started a new game without the miasma mod. Lets see if I can find more of these river tiles this time.

Would you look at that.

Still an issue even without rising tide of miasma mod. Also seems it has nothing to do with coastal tiles but instead with several river tiles in one spot. I'm running out of ideas besides using map editor to isolate the cause (and that sounds too much like work .)

My suspicion is that this may be a conflict with Rising Tide Miasma. I would need to take a look at how that mod works to check my hypothesis. Depending on load order (Rising Tide Miasma would need to load after EoE) the Miasma generation code or Miasma Repeller code could have been messed up.

I think I already ruled that out as the last post here says. Or do you think the mod left some "residue" even when it was disabled?

Bah sorry, I missed that. Do you have a save file from the game that has this issue that was only using Echoes of Earth? I want to load it up and take a look.

I'll put it up on a server tomorrow if I can still find it. Mind that it has the other mods enabled so it is not a pure EoE save.

Tomorrow changed into a week. Sorry I've been lazy. Save from a new game can be found here on my google drive, hope this works https://drive.google.com/open?id=0B58kjam2SM4oRFB4VFdqXzBQUGc

List of the mods used

Aliens - Unlimited Experience
Artifact helper
Awesome Stations
EoE
Enhanced promotions
Higher Contrast Sponsor Colors
Martial Law Decrease
Marvel Yields
Quests - Station Spawn Allows Choice of None
Rising Tide of Aliens
Rising Tide of Miasma
Units - Explorer Affinity Upgrades
Worker - Miasma Immunity

Here's a picture of the problem tile to help you find it (South of Aintza, close to capital) here.

The North West tile of Gran Éxito in that save (if it's found already) also has this farm bug.

Just started a new game with only EoE mod. Lets see if I can find an unfarmable spot.

Oh an update hit. Here we go again then :)

Thanks for providing the save, I'll take a look at it. Sorry I didn't get around to it sooner, I was pushing hard to finish the Virtue update.

I'll try to reproduce this problem with just the EoE mod in a few weeks time. Should have the time and motivation after a little hiatus. Plus I'm not going to buy CIV VI before the holidays for time management reasons so BE is my only choise :)

I was able to build farm on a plot with miasma on it. This wasn't possible before and I don't notice mention of it in the changelog. Is this an intented change to the whole mechanic or caused by having culture traits like the worker miasma immunity or +1 food from farms?

I'll find out if I can reproduce the bug later today or next weekend. So far looks good ie spots I thought wouldn't let me farm did let me build a farm.