IE10/11 Ajax XHR error - SCRIPT7002: XMLHttpRequest: Network Error 0x2ef3

The OP provided a WireShark capture showing that the server requested a certificate using the HTTPS CertificateRequest message and the client then immediately FINd the connection.

After configuring the server not to request a client certificate, the problem went away.

Using Fiddler also would make the problem disappear because, unless you configure it to do so, Fiddler will never request a client certificate from the browser.

I'm wondering if only the affected client machine had a matching certificate and/or whether the withCredentials flag on the CORS XHR request is relevant in this scenario.

I was seeing this error randomly with IE 8+9+10+11 Ajax calls. All other browsers did not have the problem.

It suppose there was a race-condition between KeepAlive connections. I am using Apache 2.4.7.

With the Apache 2 default settings in /etc/apache2/apache2.conf I was able to reproduce the error about every tenth Ajax call:

KeepAlive OnKeepAliveTimeout 5

Solution: Either setting

KeepAlive off

or

KeepAliveTimeout 1

solved the problem for me. I recommend anyone experiencing the 0x2ef3-Network error to fist set KeepAlive off on the server. If the error is gone, switch it on again and test with the values of KeepAliveTimeout. They can also be set to ms.

There is also a way to disable KeepAlive only for Internet Explorer.

In my environment, I first copied/pasted some old codes to take use of. So the "contentType" was "application/json".

When I found out IE11 over windows 8 does NOT work in a very high probability, as long as I clicked submit button using my mouse.But I also found out the if I pressed the enter key in my keyboard, then it works just fine with IE11.

Note that my input elemnts and submit button were nested in a form element.

After struggling for a while, I came to this page, but didn't solve my problem, because I knew nothing about backend technologies. I was just a front-end guy with limited knowledge.

Then I tried a lot of modifications one by one. Suddenly the jQuery official API documents inspired me. I commented out the "contentType" parameter so that the "contentType" takes the default value, which is "application/x-www-form-urlencoded; charset=UTF-8". Then problem is solved.

Hope this will help.