“CAUTION: provisional headers are shown” in Chrome debugger

Question

I noticed a strange caution message when looking at downloaded resources using Google chrome inspector (F12):

Caution provisional headers a

Answer 1

This was happening for me, when I had a download link and after clicking on it I was trying also to catch the click with jquery and send an ajax request. The problem was because when you are clicking on the download link, you are leaving the page, even it does not look so. If there would no file transfer, you would see the requested page.. So I set a target="_blank" for preventing this issue.