Game updates, improper shutdowns, or antivirus interference can corrupt the sound files.
If compatibility layers and sound driver toggles fail, the issue may stem from configuration file corruption or operating system security features. Step 1: Force a Default Configuration Reset
Most legacy Call of Duty titles require an active recording input device to successfully initialize the Miles Sound System. If you do not have a microphone plugged in, or if "Stereo Mix" is disabled, the system throws an initialization error. Call of duty exe err mss init failed 150
Since the error is audio-related, ensuring your sound drivers are updated is crucial. Right-click the Start button and select . Expand Sound, video and game controllers .
How to Fix the "Call of Duty exe err mss init failed 150" Error If you do not have a microphone plugged
Look for (often tied to Realtek Audio). Right-click it and select Enable .
Allow Steam a few minutes to scan the files. If it finds that mss32.dll or related audio data is missing, it will automatically download a fresh copy. 4. Manually Restore the mss32.dll File Expand Sound, video and game controllers
This error frequently hits players who use unofficial game modifications, community patches, or separate multiplayer clients (like old-school LAN tools). If you run the executable file ( iw3mp.exe , cod2sp.exe , etc.) from your Desktop or a separate Downloads folder instead of the master directory, it will fail to load the required audio files. Locate your Call of Duty shortcut or .exe file. Right-click it and select .