I get this error when uploading videos downloaded to iPhoto from a iPhone 4s to YouTube using Safari, Firefox and Chrome.

I have not edited or enhanced these files/videos.  I have successfully uploaded many videos in the past.  This started a couple weeks ago, approx.

I have not made any changes (intentionally) to my phone or my youtube account.  No setting have changed that I am aware of.

My iMac and iPhone are up to date with all patches.

I tried searching but I cannot find a solution.  Can you please help me?  Thank you so much for your time!