I am developing a website that uses the html cache manifest (AppCache). I often see the following line in Chrome's console:

Application Cache Error event: Manifest fetch failed (6)

Apparently the error code in parentheses is meant to be the HTTP status code, or -1 if the browser is offline. But my server is not returning 6 as status code. So what does this code indicate?

Chrome's behavior regarding this error is very odd. If I force it to re-download the website by removing the appcache client-side (via chrome://appcache-internals), this error often still occurs, but this time not preventing but interrupting an already running download; the second refresh then works fine.

The problem occurs regardless of whether there is a new version of the cache manifest or not, and this makes it hard to update Chrome's appcache. The problem does not occur in IE 11.

I'm using TLS with a self-signed certificate for this development stage. The HTTP response headers for the appcache manifest are HTTP/1.1 200 OK Accept-Ranges: bytes Cache-Control: no-cache, must-revalidate Content-Encoding: gzip Content-Type: text/cache-manifest; charset=utf-8 Expires: -1 Last-Modified: Fri, 11 Apr 2014 07:49:30 GMT Pragma: no-cache Vary: Accept-Encoding Date: Fri, 11 Apr 2014 07:51:38 GMT Content-Length: 480

  • Tag wishlist: "appcache" "error-code"
    – user37571
    Apr 11, 2014 at 8:08
  • I have exactly the same issue but nowhere can explain the (6) bit. I don't know if it helps, but I get this from a browser running in a terminal server session and it's trying to access the site on the same network; an intranet basically. Accessing the same site externally works fine. Exactly the same code. Both IIS setups are exactly the same too. So frustrating as FF and IE work fine. Somebody out there must have had this and managed to fix it? May 19, 2014 at 16:11
  • From the looks of code.google.com/p/chromium/issues/detail?id=315167 and the less-relevant readynas.com/forum/viewtopic.php?t=75968&p=423394 , it appears that this is a Chrome issue which is not fully resolved.
    – user35138
    May 20, 2014 at 5:38
  • I am currently seeing this error when the browser is not offline but my development server is. I doubt that was the case when I originally ran into this issue, but I've changed my setup so much, I can't exactly verify that there wasn't some unrecognized problem preventing the browser from actually getting server responses for the manifest.
    – user37571
    May 20, 2014 at 19:37
  • I am getting this issue in the same environment as you @pyramids. When the browser is not offline (I am still connected to the internet) but my local server is offline. Nov 3, 2014 at 10:26

3 Answers 3


Looking into Chrome source code, those numbers 6, 9 or similar are order numbers of enum. In case of 6, this is NETWORK_ERROR, in case of 9 it is SECURITY_ERROR.

Here is source showing that if given error is SERVER_ERROR it will put response code, but if it isn't SERVER_ERROR it will map its error to enum value, and this enum is defined here and the codes are:

  • UPDATE_OK (0)
  • DB_ERROR (1)

To be honest I saw only 4 when server was sending 302, 9 when certificate is wrong, and 6 but here I still don't understand whole problem.


If you still get this problem, make sure...

  • You don't have switched on "Google Chrome can run in background" option
  • Go to $sysdrive$\Users\$youraccount$\AppData\Local\Google\Chrome\User Data\Default\Application Cache -> delete files and folders

I had exactly the same issue when using Application Cache on Chrome v38.0.2125.111 m. Tried several different manifest configs but in the end I simply closed Chrome and reopened it again. Hey presto, issue was gone and cache was working fine! Hope this helps someone!

  • 1
    I'm more concerned with the question of this happening to users. If it occurs as you describe, people who are affected may not see any updates until they restart the browser, which for some power users could be as far away as the next chrome update.
    – user37571
    Nov 4, 2014 at 21:00

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