When you send a POST request by using
ServerXMLHTTP, and the response from an HTTP/1.1 server does not contain a Connection header, and the HTTP/1.1 server keeps the connection alive after it delivers a response to an HTTP request,
ServerXMLHTTP may stop responding (hang) until the timeout expires, and you may receive the following error message:
msxml3.dll error '80004005'
Unspecified error
WinHTTP attempts to read more data than will actually be delivered in the socket connection.
A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem.
If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, submit a request to Microsoft Customer Service and Support to obtain the hotfix.
Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site:
Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.
The English version of this fix should have the following file attributes or later:
Date Time Version Size File name
-------------------------------------------------------
27-Jun-20001 12:38 8.10.8627 1,106,944 msxml3.dll
27-Jun-20001 12:36 8.10.8627 24,576 msxml3a.dll
27-Jun-20001 12:36 8.10.8627 44,032 msxml3r.dll
27-Jun-20001 12:36 6.0.2462.0 28,672 xmlinst.exe
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.
The HTTP stack that MSXML3
ServerXMLHTTP uses, WinHTTP, is an HTTP/1.0-compliant stack with support for persistent connections.
ServerXMLHTTP uses a COM Automation component called
WinHttpRequest that is based on the core WinHTTP Win32 application programming interface (API).
Section 19.6.2 ("Compatibility with HTTP/1.0 Persistent Connections") of the HTTP/1.1 specification (RFC 2616) contains the following text:
Persistent connections in HTTP/1.0 are explicitly negotiated as they are not the default behavior.
When an HTTP/1.1 server interoperates with a 1.0 client, the server response to a request should specify whether the connection is closed or persisted after the response is delivered.
WinHTTP supports persistent connections, but assumes that the server will close the connection if the server response does not include a Connection header. This is the opposite behavior of an HTTP/1.1 client, which assumes that the connection is persisted unless explicitly informed otherwise with a Connection: Close response header.
Furthermore, the
WinHttpRequest component ignores any Content-Length header in the response. It does this because occasionally the value that is given in the Content-Length header is incorrect, so
WinHttpRequest continues to read response data from the TCP socket connection until it encounters the end of the response stream. However, if the connection is persisted, the Content-Length value must be honored so that no attempt is made to read past the end of the response data. Because the connection is persisted,
ServerXMLHTTP stops responding if WinHTTP attempts to read more data than will actually be delivered in the socket connection.