It seems like a bug, didn't work for me, too. (guess you play on the "1e"-version map, too)
I myself went into creative-mode and destroyed it then. ^^
Even changing the item filter to accept cobble and completely filling the chest didn't open the door. I found another way without having to go into creative, but I don't like having to workaround if possible
 
				
		


 jordsta i wish you add more quest to the 3rd quest line (monster under bed or smth like that?) i mean, after weak blood orb--->bunded sword. i was like lol. and i had to do that too to unlock other quests right?
 jordsta i wish you add more quest to the 3rd quest line (monster under bed or smth like that?) i mean, after weak blood orb--->bunded sword. i was like lol. and i had to do that too to unlock other quests right? 

