Response.TransmitFile not working on local network

[Member 3426936]

All, This is a strange problem, I tried to find answer without success. The file I am tring to transmit is an xslx file. I have the following piece of code that works fine when our employees/clients access our website from outside our network.

Response.ContentType = "application/vnd.ms-excel";
Response.ContentEncoding = System.Text.Encoding.Default;
Response.AppendHeader("Content-Disposition", "attachment; filename=" + newFile.Name.Replace(" ","_"));
Response.AddHeader("Content-Length", new System.IO.FileInfo(newFile.FullName).Length.ToString());
Response.TransmitFile(newFile.FullName);
HttpContext.Current.ApplicationInstance.CompleteRequest();

But when someone within our local network/office accesses this website I get the following error, "Unable to download xxxx from xxxx.com. Unable to open this Internet site. The requested site is either unavailable or cannot be found. please try again later." I tried different approaches like adding Response.Flush() and Response.End() etc., nothing worked so far, I appreciate any help with this. This only happens with IE, works fine in Chrome and Firefox, if this helps.