I was able to publish locally, but not upload the zip file to Connect.
I gave up last night after many hours.
This morning I tried again and got the same error, as did a colleague who was able to publish other files. I reduced the audio bit rate, which actually made the 29MB file size 300K larger!
I don't know why, but then I was able to publish the file even though all I changed was the audio quality. Apparently Captivate healed itself. The published file shows as "Adobe Captivate" under "type," which it wouldn't last night.
Thank heavens Captivate is working again! Unexplained disasters like this are why people fear using it.
Thanks for your comments,
KPetersen