Does it say "Unable to publish at this time: Please try later"? I have had this error happening since last October: eventually it was picked up by an Adobe employee in this forum, who replicated the error when I sent him a copy by email. He said he had forwarded it to the Development Team, but I have heard nothing since, and the error has not gone away. Not a lot of point of Express if you can't publish. I will stick to PDFs!
Your colleague Tarun Saini earlier asked me to resize the pages, and after I did that, it did publish. I have just tried that again, and it worked perfectly!
I hope this resolves the issue for others as well.
Great, thanks for confirming! Sorry it took this long.
The bug was related to fractional page sizes (in pixel units), with the workaround to round up/down page sizes to whole numbers. With the bug fixed, that workaround should not be needed.