Why cant I summon the wall of flesh?
I see two possibilities:
- You were not in the Underworld (where you see the background with the rivers of lava). Dropping the doll into lava in higher layers does not work.
- You think you threw the doll but you actually tried to use it by selecting it on the hotbar or picking it up and then right-clicking. Throwing is a different action (usually on the 't' key). If you see the doll fly into the lava and it's gone from your inventory, then you threw it.
Make sure you're actually dropping the guide doll into lava that is deeper than 1/2 a tile.