The Shop only change stock every 24 hours (thought it was more frequently earlyer), so if trader only got 15 milk that day you can't progress further that day.
An easy fix would be to make the Shop change stock more frequently.
If shop updated often it would fix other problems in game:
- Random quest ask for flour before you got Mill built.
- Concrete's unbalanced recipe. (droprate VS recipe requirement VS reward)
- Milk, butter, cheese could be bought more frequently
I am on last island now and on the "Imminent Eruption" quest, so guessing i have seen most of the content now.
With that in mind, i have a few other suggestion to the developers;
- Lower the time to cut Large Tree on first island from 30 min - to 10 min.
- Reduce the cost of workers bought after 9 workers owned. (i have played aaaaaalot and never gotten more then 10)
- Increase the money reward on random quest by ALOT. Atm the random quests eat up all your money. Items they ask for give you less in reward then the shop would pay you. +Random often ask you to buy/sell (earn/use), so you end up buying/selling stuff you otherwise wouldnt have. The increased spawn of random quest is very nice, BUT no money left to buy workers or tools or anything if you try to do as many random quests as you can. Workers are often buzzy just cutting trees or rocks instead of making gold, and the crops they ask for pay only half the price you would have gotten selling it yourself.
There are other issues like workers getting stuck until trees or rocks are removed, Trees and rocks spawning in the middel of farmplots. Workplaces where you loose all reward if a tree or rock is next to it, missing animation of the workers that work in buildings in your worker-panel (so you end up sending more then 1 worker to same building and none of them can move until work is done). But if the other things i mention earlyer is fixed - one can still REALLY enjoy this game even with the other issues mentioned.
A big thank you to the developers for this game. I have enjoyed it. Hopefully your next project will be revealed soon. If you need a tester.... hint hint. lol
Edit: forgot to mention. After an update (2 updated ago) - there was a buggy item added to the shop. It shows up without any icon or price, and if you click it the game crashes every time.