If the file is missing from the main Steam directory, downloading a fresh installer from Steam Support and running it over your current installation can repair the core files.
The file steamclient64.dll is a critical 64-bit dynamic link library used by the to handle core functions like connection management, inter-process communication, and Steamworks SDK features for games. steamclient64.dll
Right-click the Steam shortcut and select Run as administrator to ensure it has permission to access the DLL. If the file is missing from the main