Many antivirus programs, including Windows Defender, flag this file as a threat, especially in non-Steam versions of games.
Experts strongly advise against downloading individual DLL files from third-party websites. These files can contain malware or be the wrong version for your specific game.
Instead of searching for a manual download, use these verified methods:
The legitimate file handles user authentication, achievements, and DLC ownership. How to Fix the Error Safely
The file is not a "driver" in the traditional hardware sense; it is a Dynamic Link Library (DLL) used by the Steam Client API to help games communicate with Steam. If you see an error saying this file is missing, it is usually because your antivirus quarantined it or the game files are corrupted. Core Review: Should You Download It?
If you own the game on Steam, let the platform fix itself: Right-click the game in your Steam Library . Select Properties > Installed Files (or Local Files).