Just figured this one out thanks to another forum, was driving me crazy. Sign in to your youtube account online, I did mine using my google account name that I've had for years.
Now go to your youtube homepage, and click "My Channel." Click to create your own channel, and it make you log out of google and choose a channel name. Then it will pop up and let you link your channel to your google account.
Once that's done, the error goes away and you can upload.