Why is there sound missing from the end of my videos?

[Windows Central Question]

I recorded some short videos on my lumia 830 (10-15 seconds), and although they play fine on the phone itself, when I send the videos to people of copy them to my computer, the last 3-4 seconds of sound is missing. I have tried copying them to the computer, sending them in messages and uploading them to one drive but the result is always the same.