Modifying the game or attempting to play it offline without a proper connection can cause verification mismatches. If the DLL version does not align with the current executable update patch of Hitman: Absolution , initial handshakes fail. Safe and Effective Resolution Strategies
Wait, is "Professional Edition" a legitimate edition of the game? I should check that. As far as I recall, Hitman Absolution was released with a standard and a limited edition, but not a Professional Edition. The user might have confused the title, maybe they're referring to a different mod or a third-party edition. Hmm, but maybe in some regions or through third-party sellers, different edition names were used. I should note that for accuracy and suggest checking the official store page.
: If the game fails to launch with a "steam_api.dll not found" error, it is likely that your security software quarantined it.
Once you've fixed the problem, take these steps to prevent it from happening again: