There seem to be three variations of the disappearing fertile tiles.
- The encampment destruction version. This one is caused when you destroy an encampment and its effects are temporary. See the screenshots below;
- The enemy city version. I have no screenshots, but i will try to explain: Say there is a fertile tile, but the SK builds a city on top of it before you reach it with a settler. After conquering/destroying that city the tile will have lost its fertile state permanently (no grain or hammer icons).
- The quest location version. Also no screenshots, again an explanation: Say you have a fertile tile and you get quest which creates a building on top that tile, after you complete the quest the building disappears and the tile becomes free, however it may have lost it fertile state.
The first and third versions seem to be happening randomly, but the occurrence of the second version seem to be a near certain loss of fertile state for the tile. Saving and reloading will not restore the fertile state of the tile for the second variant.
The thing in common seems to be that yields disappear when a tile is altered by an event.
The encampment destruction version.
After destroying encampments sometimes fertile tiles are no longer settleable.
Saving and reloading seem to restore the tile states.
Before the fights and destruction of the encampment.
Note the grain and hammer icons to the north and east of the encampment. The tile on which the encampment is located is actually also a fertile tile.
After the destruction of the encampment.
Note the missing grain and hammer icons on some of the tiles. When moving the settler to this location you can build an outpost, or settle a new city.
After saving and reloading, the icons are back and you can see where your settler can found a new city.
