Event ID 200 — BITS Client Connectivity

Applies To: Windows Server 2008 R2

In order for the BITS client to successfully complete files transfers, the client must be able to connect to a BITS server that is available on the network.

Event Details

Product: Windows Operating System
ID: 200
Source: Microsoft-Windows-Bits-Client
Version: 6.1
Symbolic Name: EVT_PROXY_ERROR
Message: While transferring %1, BITS encountered error %2 using %3 as the HTTP proxy server. This may indicate a problem with the proxy server or with the client's network configuration. If this error occurs frequently, an administrator should investigate. Details: {Job: %4}, {owner: %5}, {jobid: %6}, {URL: %1}, {xferId: %7}, {proxyServerList: %8}, {hr: %2}.


Ensure that the HTTP server meets BITS requirements

To resolve this issue, ensure that the HTTP server meets BITS requirements.

BITS supports HTTP and HTTPS downloads and uploads and requires that the server supports the HTTP/1.1 protocol. For downloads, the HTTP server's Head method must return the file size and its Get method must support the Content-Range and Content-Length headers. As a result, BITS transfers only static file content and generates an error if you try to transfer dynamic content, unless the ASP, ISAPI, or CGI script supports the Content-Range and Content-Length headers.

BITS can use an HTTP/1.0 server as long as it meets the Head and Get method requirements.

To support downloading ranges of a file, the server must support the following requirements:

  • Allow MIME headers to include the standard Content-Range and Content-Type headers, plus a maximum of 180 bytes of other headers.
  • Allow a maximum of two CR/LFs between the HTTP headers and the first boundary string.


Confirm that the proxy servers support HTTP 1.1 RANGE requests. If RANGE requests are enabled, BITS will automatically retry the job.

BITS Client Connectivity

BITS Infrastructure