Http call not working

I am calling a web service from my Desktop Application, But it is only working on Windows 10 machines which i tried so far.
On Other machines (Windows 7) httpSocket throws Runtime error - “Error occurred while sending request (likely a bad url)”

I am using following code to call web service -

dim mysocket as new httpsocket1 //Xojo.Net.HTTPSocket

Dim params as Text= “trans_amount=”+Amt+ “&invoice=”+Inv+ “&refnum=”+Ref

dim postData as xojo.Core.MemoryBlock = Xojo.core.TextEncoding.UTF8.ConvertTextToData(params) //params have my parameters
mysocket.SetRequestContent(postData, “application/x-www-form-urlencoded”)

Any one know what i need to do to get it work on all windows OS versions?

Look at the Language Reference for Xojo.Net.HTTPSocket. There is a good chance the service you are connecting to requires TLSv1.2. The LR tells how to fix that.

Do Amt, Inv, or Ref contain characters that aren’t allowed in a URL? i.e. any of the following: ! * ’ ( ) ; : @ & = + $ , / ? % # [ ]