The Sewers is an area in Stardew Valley that you will be able to unlock using the sewer key. The rusty key or the sewer key is available from the Museum. If you donate at least 60 items, Gunther will give you the key and you’ll be able to unlock The Sewers.
There’s also the Statue of Uncertainty, in which you’ll be able to change your professions for just 10,000g.
Wanna change your appearance? Check out this guide.
Stardew Valley Sewer Key Bugged and Not Working
It’s quite rare, really. But there’s a bug that many players have encountered in the game. There’s a certain Reddit thread where played had encountered a bug but it’s unbeknownst to the creator themselves.
However, this bug only happens when you install multiple mods and there’s a possible conflict between the files. When you’ve reached the bottom of the mines, completed Krobus’s event, and got the key, you might encounter a possible door entry bug.
It was resolved after a few several patches, so don’t worry much.
You can learn a few cooking tips by checking this cooking guide.
Sewer Key Multiplayer
I think this one’s bound to happen one way or another. But the common thing to happen is when you or your friend wasn’t able to unlock the sewers in separate progress.
You need to make sure that when you go to multiplayer, you and your friend already got the sewers area unlocked.