The file is a critical dynamic link library file utilized by the Steam client to manage game authentication, achievements, social features, and digital rights management (DRM). When launching Dark Souls 2 (specifically the 64-bit Scholar of the First Sin edition), a missing, corrupted, or blocked steamapi64.dll file will prevent the game from starting, usually resulting in a crash or a specific error popup stating that the file was not found.
: Sudden system shutdowns or interrupted updates can damage the library file. steamapi64dll dark souls 2