I forgot to mention that you must have at least 1 item in your inventory that you want to add.
The error appears because the code cannot find "ore4" in your inventory.
Was this always considered a puzzle game? I feel like last time I played it, there were definitely some puzzles/minigame, but it still felt more mainly like a sandbox styled visual novel. Did development or the direction of the game change in the last couple years or was it always considered a puzzle game? I feel like I wouldn't have picked it up the first time if it was.