My island is level 30 and I clicked on the craftsman challenge and it said I completed it. I have no clue why it did this but all I did is I made it to level thirty was chatting some then opened it and clicked it because I was curious as to what it would say. I have no clue as to what can be done about this honestly.
I'd say it's working since it now says "your island level must be 75 to complete this challenge". However it still says I've completed it and I don't know what to do with the obsidian and whatever else it might've given me.
I got this reward at an early level as well. I would assume you keep it, don't really matter to much. However, sure Andrew/Jamie can confirm
