Do you get an actual error message or does it just look like it times out? Once the video has rendered you enter your account information and it says log-in successful. At that point it is uploading the video but the progress bar does not always work to show this (this is a reported bug we are working on). The size of the video obviously dictates the time the upload will take. I have included a couple of links below to helpful YouTube pages in our help section as well.
How to share your scribe - video