Getting HTTP Error 500.19 - Internal Server Error while accessing the website

I have a asp.net web application which acts as a wrapper for the report server. I make a http web request and read the response from the SSRS using SteamReader and then use StreamWriter to write this response back to the browser.

var request = (HttpWebRequest)HttpWebRequest.Create(uri);
var response = request.GetResponse() as HttpWebResponse;

I have implemented custom authentication and everything works in SSRS 2016, but I am facing problem with SSRS 2017. When I make a web request from our web application, I am able to get the response from SSRS but when I try writing back the respose to the browser we get HTTP Error 500.19 - Internal Server Error.

While debugging, I noticed that the Response.ContentEncoding is "gzip" so I've added the below line of code to decompress it

request.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;

var text = new StreamReader(response.GetResponseStream()).ReadToEnd(); 
streamWriter.Write(text);

Now I am getting the proper response text that is expected, however when I write the response stream to the browser, the page displays HTTP Error 500.19 - Internal Server Error.

Module DynamicCompressionModule Notification SendResponse Handler AFRaspx7 Error Code 0x8007000d Requested URL https://10.xx.xx.x:448/Reports_2017/Browse Physical Path C:\Program Files*****\Web Service\Reports_2017\Browse Logon Method Anonymous Logon User Anonymous Request Tracing Directory C:\inetpub\logs\FailedReqLogFiles

Can anybody tell me what can be the cause of this?

Thanks,

Anitha John