Cannot Publish to You Tube (Captivate 6). Help!

I noticed this question in another spot, but the answers provided don't work for me. I'm trying to publish a project to Youtube, using Captivate 6 (most recent version-updated yesterday) on a Mac (OS 10.9.3). When I last used it (in October 2013), it worked fin. Now I get an error box and, even though I let it go through the entire loading process, the Adobe Captivate Video Publisher box is blank and no matter how long I wait, I just get the spinning beach ball. The box for creating the video is at 100%, but I can't move further. I've used this product for a number of years and am disappointed that this isn't working. I should note that all other aspects of the software (creating and saving a project, adding audio, etc.) are working just fine.

Thanks for any help--I'm in a time crunch and this isn't helping!