"steam-api64r.dll is missing" Mortal Kombat X typically occurs because your antivirus software has incorrectly flagged and quarantined the file, or the Steam client failed to install it properly

Look for a recently blocked item related to steam-api64r.dll . Select > Restore .

To prevent it from happening again, go back to Virus & threat protection settings > Manage settings > Exclusions (Add or remove exclusions) and select the Mortal Kombat X installation folder. Method 2: Verify Integrity of Game Files on Steam

DLL files downloaded from unverified third-party sources present severe security risks: They may contain embedded malware, spyware, or keyloggers.

Few things are more frustrating than sitting down to enjoy some gaming, only to be greeted by a cryptic error message instead of your game's launch screen. If you're a Mortal Kombat X player and have encountered the "steam_api64r.dll is missing" error, you're not alone. This issue has frustrated many PC gamers attempting to play the iconic fighter, but it's almost always fixable with the right approach.

Overzealous antivirus software (especially Avast, AVG, and Windows Defender) sometimes flags this DLL as a false positive and quarantines or deletes it. The game then can’t find it, and you get the error.