Try each solution in the order listed. After you attempt a fix, always restart your game to test if it worked. This methodical approach will help you pinpoint the exact problem and get you back to experiencing Black Ops 3's intense futuristic campaign or surviving endless waves of zombies in no time.
Select and then Exclusion (or "Allow") to prevent future deletion. Verify Integrity of Game Files
If none of the above works, it is possible that the Steam installation structure for the game has deeper corruption.
If you've tried all the above methods with no success, a full reinstall is your final, fail-safe option. Try each solution in the order listed
How to Fix "steam_api64.dll Missing" Error in Black Ops 3 [Verified Solutions]
Method 1: Verify the Integrity of Game Files (Most Reliable)
Download and install the from the official Microsoft website to refresh your DirectX files. Select and then Exclusion (or "Allow") to prevent
Always use official sources (Steam or Microsoft) to recover system files.
Sometimes missing system files cause the DLL error indirectly.
Wait for Steam to scan your installation. This process may take several minutes. Once finished, Steam will automatically download any missing files. Method 3: Reinstall the Steam Client How to Fix "steam_api64
Since antivirus software is the most common cause, this is the first and simplest check.
Navigate to the (or Local Files ) tab on the left menu.
To prevent your antivirus from deleting the re-downloaded file again, you must add the game directory to your security software's exclusion list. Open > Virus & threat protection .
If verification doesn't work, you can download the file from a dedicated source like DLL-Files.com .