What kind of network error is Chrome encountering when 'Status = (failed)' and 'Type = undefined'

Question

Sometimes I randomly see network requests from Chrome failing with Status = \'(failed)\' (status code 0 from the request object in JavaScript) and the response type as \'und

Answer 1

I ran into this while working on an ad serving network. It ended up being the AdBlock Plus Chrome extension blocking any assets, probably the "ad" in the path. I whitelisted my domain and it worked.