For anyone finding this thread, please see this comment: Error adding Crop Variety in Crop Plan
if you are self-hosting, and want to try this module out, be warned: IT IS NOT STABLE AND WILL ABSOLUTELY BREAK AND LOSE DATA. We are still very early in the development, and are not going to be writing automated database updates for changes to the module until a beta is officially released. You are welcome to try it out, but DO NOT USE REAL DATA. You have been warned. 