I reset my browser setting and I use Google Chrome but.. my video upload time was very fast! To which I cant believe. A take me only 10 seconds to get to 50% loading. However when it reach 50% it stopped. When I went to my 'Video Manager' tab it say "Processing...". Been hours! What more? The first two video I had uploaded have the same problem. The reason why I could upload is because I keep the "upload" tab open. However, I wanted to know what cause this.
This is a known glitch on YouTube's end. Best to cancel and try again. This happened to me for several days. I cleared cookies/cache, everything and started it up and eventually it worked.
Recently, I have been getting a new issue. When I upload, I can't use my internet at all! It's almost as though I am being blocked. This may be a Comcast issue and not YouTube, but it's strange how it happens either way.