You sir, are a legend!

Thank you for this advice. I had been struggling to upload to d.tube months and decided it wasn't worth the trouble. I wish I had seen your reply earlier.

Thanks to rgeddes excellent guide (located here: https://steemit.com/steemit-guides/@rgeddes/getting-your-posting-key---made-easy)

I was able to find my PPK, and login to d.tube without using SteemConnect. I am now able to upload without an errors! AWESOME!