Build Upload Failed

I am having a problem uploading the latest build for my game to the Alpha channel.  I've found several similar posts, but in each of those there's at least some sort of error information.  Here's what I get...

Not a lot to go on there.  In case it's something to do with the version numbering, I am attempting to update from build version "0.3asw.153" to "0.3b.160" --I tried rebuilding as version "0.4.160" but that fails exactly the same way.  I'm reduced to shots in the dark with no error information at all.

I'd be grateful for any suggestions how to resolve this issue.