Fixing Game Sounds - ViaMods/Black-Ops-3-Mod-Tools GitHub Wiki

If you're not in the USA you most likely are having issues with not having game sounds.

To fix this go to your Control Panel and clicking "Change date, time or number formats" under the "Clock, Language and Region" category.

The settings you will want are like this:

Once you have done this you will need to reinstall your mod tools, and you should have game sounds again.

Tutorial courtesy of Byte