First it said if you have a Firefox then update it to Firefox 4 or higher, but mine was already up to date.
Then it said use "Firefox Private Browse" to upload the video, I did that but that didn't work aswel.
Then said "Temporarily disable anti-spyware, anti-virus, or similar software" I thought forget it and let me try with Google Chrome. So I downloaded Google Chrome and installed it, then tried to upload and it worked.
* If you using Firefox then download Google Chrome and try with it, it worked for me.