You have to find a key in the Flutewood, and then use it on that door.
13 days ago(+1)
oh that's because there is a bug that gets you stuck in an infinite loop at the house, it should be fixed come next update.
Not really. Something about misclicking and dropping the silver coin instead of inspecting it and then trying to pick it up. But when picking it back up I got another mud coin. Then when I tried to drop it I got another mud coin in the world but it stayed in my inventory. Then it got duplicated, now I can duplicate it infinitly. Thats all I remember, hope this helps