A corrupt download cache can cause Steam to mis-deliver DLL files.
This is the official Steam method. It will scan your game folder and automatically re-download any missing or corrupted files, including steam_api.dll.
But the safest method:
Antivirus software is paranoid by design. It often thinks steam_api.dll is a "generic crack" or "hacktool" because it modifies game behavior (e.g., enabling the overlay).
For Windows Defender (Windows 10/11):
For Third-Party AV (Avast, McAfee, Norton, etc.):
steamapi.dll is a Steam client file. The error means either: dishonored steamapidll is missing
✅ This guide assumes you own a legitimate Steam copy of Dishonored.
This is the most effective fix for 90% of users. Steam will automatically scan for missing or damaged files and download fresh copies. A corrupt download cache can cause Steam to
Step-by-step: