I uploaded a tribute to something (Look to the left ;p) and incuded a song to make the tribute more "Meaningful". I later get a message saying something about third party content. I read about it, but i still do not understand what it is. What is this third party content?
Third party = Something that isn't in any way related to the current establishment (in this case, EMC) Other people have been able to do it in the past, though. I don't know why you can't.
If you used copyrighted work or a copyrighted song, it will not upload, or get you a copyright flag. Sorry but, this is only what I can think of :/
Usually this occurs when you use copyrighted material or material that you don't own or have the permission to use that content, you can always read this to avoid another situation like that. This is also why some youtubers don't include music in their videos to avoid these. http://www.washingtonpost.com/wp-srv/guidelines/third-party-content.html