google-chrome - err_unexpected - failed to load resource: net::err_name_not_resolved

Bizarre Error in Chrome Developer Console-Failed to load resource: net::ERR_CACHE_MISS (4)

As far as I can tell, this error was not being thrown yesterday on Chrome, and as of this morning, it is. I have not changed any of my browser settings. I have attached a screenshot (after opening/closing Developer Tools window four times):

This issue is tangentially similar to Stack Overlow post Failed to load resource under Chrome except that it only occurs when I "Inspect Element" in Chrome. Here are the details I have:

To the best of my ability I undid everything I did since last night (when I did not have this error) and the error persists. When I remove all pre- <html> PHP code, the error disappears.

When I only remove all the pre- <html> PHP code except

<?php session_start(); ?>

the error returns.

Since the error seems to involve PHP, I checked my error log, but there are no notices, warnings, nor errors. When I close the Developer Tools window and then open up the window without a page reload, the number of errors increments by one each time.

When I keep the window open, and then reload the page, the page reloads without throwing the error. However, as soon as I close the Developer tools window again, then open it (no page reload), the error is thrown. I checked my site on Firefox with Firebug enabled, and no errors are thrown, making it seem like a Chrome issue (version 38). My site seems to function normally otherwise. Other sites on device browsed via Chrome (for example, Yahoo) also experience this error.

Also, I have not manually changed any of my browser settings since months ago. As an additional note, this is the second strange error I have encountered in Chrome in the last year (see Stack Overflow question Failed to load resource: net::ERR_NETWORK_IO_SUSPENDED ), to which no one was able to find a solution, even with a bounty offered.

Is there a way to prevent this error, or is this a browser-only issue? On a side note, when I open up Developer Tools in Chrome for Stack Overflow, there is no error thrown, so either Stack Overflow is not coded in PHP or they have a way to prevent this error. I think my site is not affected, but I am not 100% sure, and it makes me nervous :)

Check for the presence of words like "ad", "banner" or "popup" within your file. I removed these and it worked. Based on this post here: Failed to load resource under Chrome it seems like Ad Block Plus was the culprit in my case.

Check to see if you have previously disabled caching in Chrome when the developer console is open - the setting is under the console, settings icon > General tab: Disable cache (while DevTools is open)

On Chrome's latest update (38.0.2125.104 m at the moment), Google added the option to know whether the files loaded to the website were newly downloaded from the server - or read from the local cache.

When an error like yours "hits" the console - you know the files were just downloaded from the server and not read from the local cache. You can recreate this error by clicking Ctrl + F5 (refresh and erase cache).

It fits your description where Firebug (or equivalents) doesn't fire any errors to the console - whilst Chrome does.

So, the bottom line is - your're just fine and you can ignore this error - it's merely an indicator.