Do not use—GetRequestStream is not supported by PackWebRequest.
public override Stream GetRequestStream()
Occurs on any call to GetRequestStream. The pack URI protocol does not support writing.
GetRequestStream exists to implement the contract required by the abstract base class. The pack URI protocol does not support writing.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.