Using Gyrocopter Machine Gun Sound to a marine... I've got a problem

[Flesterage]

I started like this: I went and found the Gyrocopter Machine Gun Sound in the sound editor and clicked on ''Use as Sound''. I tested if the mission would load and no it goes to the main menu and a compile error appears (and I didn't even added the sound to the marine) If you can help me add it to the marine it would be great.