We're updating the Google framework we use to upload to YouTube, and we suspect that will fix Mac VIRB Edit's YouTube upload issues. We'd feel a lot more confident about that assessment if we were able to reproduce the problems you're running into, though.
I imagine this comes as a bit of a surprise to those of you YouTube is failing for, but we don't really see YouTube uploads fail often on our end. Even in these forums, much of the feedback is actually from people who are having failed exports, not failed YouTube uploads.
Please only respond if you have videos that can successfully export but fail to upload to YouTube from VIRB Edit.
Those of you with upload issues:
Anything potentially unique/unusual that you do that would help us reproduce these issues would be appreciated, for example:
Do you let your Mac go to sleep mid-upload?
Do you minimize or cover up VIRB Edit with another app window mid-upload?
Do you have videos that consistently do work for uploads and others that consistently do not, or are failures more random than that?
Are there networks VIRB Edit -> YouTube uploads do work for you on, and others where they do not?