Right-click your primary audio device (e.g., Realtek Audio) and select Update driver

The root causes generally stem from sound driver conflicts, corrupt game files, or hardware incompatibility. Common culprits include:

Third-party services can conflict with the game's startup process. Press Win + R , type msconfig , and hit Enter.

Broken Visual C++ Redistributables or corrupted player configs.

To prevent the "Call of Duty EXE ERR MSS INIT FAILED 150" error from occurring in the future, make sure to:

Click on again, select Set as Default Device , click Apply , and then restart your game.

: The game may lack the necessary rights to access system-level audio components. How to Fix the Error

5. Clean Install Audio Drivers and DirectX End-User Runtimes

Sometimes security software can misidentify game files as threats and block them. Temporarily disable your antivirus and firewall to test if this is the cause. If the game launches, add the entire Call of Duty installation folder to your security software's exception/exclusion list.

Corrupted Windows system files can sometimes trigger game errors.

If you're still experiencing issues with the "Call of Duty EXE ERR MSS INIT FAILED 150" error, you may want to try the following additional resources:

Incompatibility or corruption in your system's audio drivers.

The error in Call of Duty typically occurs when the game fails to initialize the Miles Sound System (MSS) , a library responsible for handling in-game audio. This issue is most common in older titles like Call of Duty 2 or Call of Duty 4: Modern Warfare and is often caused by missing DLL files, corrupted game data, or conflicting audio drivers. Common Causes

Step-by-Step Fixes for "Call of Duty exe err mss init failed 150" 1. Enable "Stereo Mix" in Windows Sound Settings

Modern headsets (especially those operating at 96kHz or 192kHz) speak a different language than the legacy MSS system (which prefers 44.1kHz or 48kHz). When your Windows audio is set to "Studio Quality," MSS chokes. It tries to initialize, sees a sample rate it doesn’t recognize, and throws error 150.

Run the game and launcher as administrator

What (Windows 10, Windows 11, etc.) are you using?

Giving the game elevated privileges can allow it to access necessary audio subsystems. Navigate to the Call of Duty installation folder. Right-click Call of Duty.exe and select .