Chunking-Content lenght-help!

An application currently works as http but need now to offload and use https. App works ok however downloads dont due to content lenght missing. have a streams profile which is required and i have tried all choices of response chunking in the http profile but still no content lenght which is why file is unknown size and wont download - any help to get around this would be great

Error:- NPHttpDownload::startDownloadBlockingChunked() - Reply Header Pair [7] [Transfer-Encoding] [chunked] NPHttpDownload::startDownloadBlockingChunked() - Failed to download file. Size unknown.

Streams profile:-

when HTTP_REQUEST {

if { [HTTP::path] equals "/" } { HTTP::redirect "/Scripts" } else {

Disable the stream filter for all requests STREAM::disable }}

when HTTP_RESPONSE {

Check if response type is text

   Replace http:// with https://
  STREAM::expression "@http://test@https://test@"

   Enable the stream filter for this response only
  STREAM::enable

}