A few years ago, Youtube changed from using the YouTube username and password to using the GMAIL user name (email address) and password. Try the Gmail email address and password if you have one.
Currently Being ModeratedJun 23, 2013 6:00 PM (in response to AppleMan1958)
Thanks, AppleMan1958 - that is not the issue, unfortunately. I had made that adjustment some time ago. This happened suddenly last week; out of the blue, iMovie stopped accepting my proper ID and password for YouTube/Google. It seems to be an iMovie glitch/issue.
I am having the same problem and I have tried everything suggested on this post:
changed my gmail password
made a specific application password
changed settings on video/sound etc.
STILL CANNOT UPLOAD AN IMOVIE to Youtube!
Need to do this for an assignment, otherwise I would give up.
Any new ideas ? help? !