WinHttpReadData Error 12002
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WinHttpReadData Error 12002


Article ID: 286515


Updated On:


Carbon Black App Control (formerly Cb Protection)


  • Errors when attempting to download the Agent upgrade package, similar to:
    Failed to download upgrade package: https://ServerAddress/hostpkg/pkg.php?pkg=/ParityHostAgent.msi. WinHttpReadData Error[12002]
  • Errors when attempting to download some other file from the Resource Download Location (RDL), similar to:
    Failed to download Server Cert List file from URL [https://ServerAddress/hostpkg/pkg.php?pkg=TrustedCertList.pem]: Error[WinHttpSendRequest Error[12002:]]. Options[00000003] TotalFailures[1] FailureId[961]


  • App Control Server: All Supported Versions
  • App Control Agent: All Supported Versions
  • Microsoft Windows: All Supported Versions


The endpoint encountered some network timeout when attempting to access the files on the Resource Download Location.

Microsoft defines this WinHttp Error[12002] as:
The request has timed out.

This error can be returned as a result of TCP/IP time-out behavior, regardless of time-out values set in Windows HTTP Services.


  1. Verify the Resource Download Location (RDL) specified is correct.
  2. Verify Port 443 to the RDL is open.
  3. Log in to the endpoint encountering the error and use a browser to validate the file exists and can be downloaded (without error), example:
  4. If a Proxy is in use, add an exception for the Server Address and/or the RDL.
  5. Perform the relevant task manually on the endpoint: