The most common cause is Windows Defender or another antivirus flagging the DLL as a "false positive" and moving it to quarantine. Windows Security (or your third-party antivirus). Virus & threat protection Protection history steam_api64.dll or a related file. and then add the file or the game folder to your Exclusions list to prevent it from being deleted again. Step 2: Verify Integrity of Game Files (Steam Users)
Because is a highly demanding 64-bit application, it requires the 64-bit version of this bridge ( steam_api64.dll ) to run. If this file is corrupt, misplaced, or entirely missing, the game cannot check in with Steam and will crash before it even displays a loading screen. Why Does the Error Happen? call of duty infinite warfare steamapi64rdll missing work