Hello, we are desperate about this issue. We've been using Easyblog for years and this hasn't happened to us before, and after it's happened to us 3 times we already think it's some kind of bug. The thing is that when a user with the role of "administrator" uploads a new video within a content will delete .MP4 files automatically... we have tried to reproduce the error but we can't because apparently it doesn't happen always, or there is something in the browser of that user that affects... BUT I DON'T KNOW HOW!
I don't know if something similar has happened to you before or by saying this I give you some hints. They always update from the backend.