Open your antivirus (like Windows Security) and check the Protection History . If the file was quarantined, you can choose to "Restore" it and add the game folder to your exclusion list.
If you see an error stating "The code execution cannot proceed because steam-apirajas.dll was not found," it usually happens for one of two reasons:
Right-click Age of Empires II in your Steam Library, select Properties > Local Files , and click Verify integrity of game files... . Steam will automatically replace any missing or official files.
Understanding steam-apirajas.dll in Age of Empires II If you have encountered an error regarding steam-apirajas.dll while trying to play , you are likely dealing with a specific file associated with unauthorized software modifications or "cracks" for the game's Rise of the Rajas expansion. What is steam-apirajas.dll?
Are you seeing this error with the or the older 2013 HD Edition of the game?