Avoid downloading steam_api.dll from third-party "DLL fixer" websites. These files are often outdated or bundled with malware; always use the official Steam verification process to replace missing files [4].
Inside the main game folder (usually containing the HMA.exe or HitmanAbsolution.exe ), look for an existing steam_api.dll . Avoid downloading steam_api
If you're using any mods or third-party software, try disabling them to see if they're causing the issue. Avoid downloading steam_api