Appmanifest_1173510.acf -

: If this file is missing or corrupted, Steam will show the game as "uninstalled" in your library, even if all the actual game data remains in your common folder.

: The file contains details like the game's name, install directory, current "StateFlags" (e.g., fully installed or update required), and "buildid". appmanifest_1173510.acf

: These .acf files (Valve KeyValues format) serve as a "map" for Steam. They tell the client that a specific game is installed, where its files are located, and what version is currently on your disk. : If this file is missing or corrupted,

The file is a metadata file used by the Steam client to track the installation, update status, and configuration of Hello Neighbor 2 (AppID 1173510). Purpose and Function current "StateFlags" (e.g.