CDN Cloud Files – Error: Unexpected response ():

Hi All,
I have been using the CDN feature with cloudFiles for years and it’s been flawless. Changed no settings, upgraded nothing, and now for the last ~2 months or so every single file is failing to upload.
When I click “Test Cloud Files Upload” I get
“Error: Unexpected response ():”
which is also the error listed on every single file that is not uploading properly.

I verified using a desktop app, I can manually upload files to my CDN container using the same username and API key. Also the files that are already in the container work just fine, and W3TC seems to know this as it still substitues the url correctly when rendering pages on my WP site.

Any ideas what could be wrong or why this has suddenly changed?

W3TC: 0.9.4.1
WP: 4.2.2

Thanks!

-Dan