Error: Human Not Found places the player in the role of Grace Fortran, a computer scientist stationed on-board the Noah Sphere, a research station in space. Instead of celebrating the success of the first Artificial Intelligence (AI) being uploaded to a physical android, Grace is racing to clear her name in the death of the AI who was found dead less than 24 hours after the upload. Work together with another AI, Ada, to search for clues, question suspects, and solve four kinds of computer-science related puzzles in this science-fiction visual-novel/puzzle game hybrid. Determine the fate of AI's and their relationship with humanity with three endings to this murder mystery. Unlock databases that give background information about the real-life computer scientists, mathematicians, and roboticist that the characters share names with.