Q:

http post not responding on windows server 2012

I am working on a software that use http post to do some things. The http post work perfect everywhere but in windows server 2012 it need specific header order. I am attaching fiddler screenshots. In the screenshots you can see that if i change header order it stop working.
Specific order works:

Changing host to other line not working:

A:

Header order is not important for headers of different names (the order of headers with the same name does matter):
RFC 2616 Section 4.2 Message Headers

The order in which header fields with differing field names are received is not significant. However, it is "good practice" to send general-header fields first, followed by request-header or response-header fields, and ending with the entity-header fields.

RFC 7230 Section 3.2.2 Field Order:

The order in which header fields with differing field names are received is not significant.  However, it is good practice to send header fields that contain control data first, such as Host on requests and Date on responses, so that implementations can decide when not to handle a message as early as possible.  A server MUST NOT apply a request to the target resource until the entire request header section is received, since later header fields might include conditionals, authentication credentials, or deliberately misleading duplicate header fields that would impact request processing.

If the HTTP server does not work correctly when the Host header is not in a desired order, then it is in violation of the HTTP specification, as the header can appear in any order and the server must be prepared to handle that.

