[Solved] The remote server returned an error: (403) Forbidden.

Try to download an image using follow code:

using (WebClient c = new WebClient())

{

      byte[] responseData = c.DownloadData(imageFileUrl);

      //.....

}

And get the following exception:

The remote server returned an error: (403) Forbidden.
   at System.Net.WebClient.DownloadDataInternal(Uri address, WebRequest& request)
   at System.Net.WebClient.DownloadData(Uri address)

Some web servers can block requests based on the user agent string they provide. Try to add the user agent of a browser, any browser would be fine.

using (WebClient c = new WebClient())

{
      c.Headers.Add("User-Agent: Other");

      byte[] responseData = c.DownloadData(imageFileUrl);

      //.....

}