(Alpha 10 dev 2395 x64) Removing farmland zone throws error

Summary: After removing farmland and reloading the game and error is thrown. Pic should say it all.

Expected Result: Removing farmland brings the land back to grass and we go on our merry way.

Actual Result: Farmland is removed however an error is thrown indicating the game still thinks it exists.

Steps to reproduce:

  1. Have a farmer and create some farmland. Plant something on it.
  2. Remove the farmland.
  3. Save, exit, and reload the game. An error will be thrown.

(The top 2 are the farmland bug, the others are from scaffolding.)

Turns out this was a symptom of a larger problem that you helped us discover. Should be fixed for the next build. Thanks!