Ah, I was about to post the same issue. I'm just about to finish wrapping up a little app but when it came to building, I've been struck with the same issues. Neither emulation nor building works, at all. When uploading, the zipping and uploading process is far too quick. It's like the assets aren't even there.
Would really appreciate a quick response on this from the Intel or C2 team.
EDIT: Just tested now with using one of the demo files instead of starting with a blank file, and it seems to work fine. I guess the blank template is just missing a file or something.
Nope, wait, it's not working. The emulator works for the most part but throws up errors often. It now uploads the whole project but again refuses to actually build the project, saying that assets are missing. I've gone through the project settings and put in icon files and unchecked all the unnecessary plugins, but it still isn't working.
Two updates: I've gotten emulation working with the blank template. Files need to be copied to the "www" folder, instead of the root of the application. I haven't used XDK in a while so I'm not sure if it was just me being an idiot and not knowing that.
Second, regular Android app building works, but Crosswalk doesn't. This isn't immediately helpful but might help someone figure out what's causing this issue.