In simple terms: without a valid steam_api.dll , your paid Steam copy of PES 2016 will not run.
: Some errors occur because the required DirectX components are not installed on the system . How to Fix steam_api.dll Errors for PES 2016 steam api dll pes 2016 link
Understanding why this error occurs is the first step in fixing it effectively: In simple terms: without a valid steam_api
The DVD version may still require Steam installation (many PC physical releases use Steam DRM). Install Steam, activate the game with the key from the box, then verify files. If it’s a truly offline DRM-free version, reinstall from the disc and apply the official patch from Konami. Install Steam, activate the game with the key
Avoid downloading steam_api.dll from third-party "DLL fixer" websites. These files are often outdated, incompatible with specific game versions, or may contain malicious software. Always use the feature within Steam to ensure you have the official, secure version of the file.