Yep, the data for main quests are neither implemented nor even programmed into the game yet jumping from Quest 27 "Fertile Overgrowth" to Quest 50 "Pickles Please" in the raw data. This should be fixed before the final release of the game. 

I posit that the reason for this change was most likely due to the witch academy adjustments that were needed for a much smoother transition in the flow of the story. Prior to this update, you could get the witch academy recommendation early, by either talking to Abby or the witch in the slums, but you couldn't actually enter into the witch academy, due to plot inconsistencies. Even after completing Royal City and the Dryad area, many people were unclear where to go next with the island being out of the way and the milk farm area being underutilized. So the creator blocked off the milk farm and limited the options so you had to go to the island next. Once complete, you would then receive the witch recommendation and sign post you to go to the Witch Academy, finally. However, upon attempting to enter you find that you still need to go to the milk farm to successfully open the way. Finally, you could enter the witch academy and the story flows normally.

I'm not saying that this isn't still a bit clunky, but it makes a bit more sense than simply bumbling around until you happen to bump into the correct solution. The island is southwest of the forest entrance on the world map, by the way.