Click on a link on C# WebBrowser to start download a file and also its link-Collection of common programming errors

I am using a C# WebBrowser to navigate to a page. After navigate to that page I extract some link from its source code and then start to navigate to those sub_links in a loop which I get from its parent url.

On every sub_links there is a link which is look like:

    Accept

the id of a button is "ctl00_UCDownloadFile1_Accept" is same in all its sub_links. When I click on above link manually a file start to download. I want to "click" on above button using c# code. I am able to click on above button using this code on webBrowser1_DocumentCompleted event:

HtmlElement elementById = webBrowser1.Document.GetElementById("ctl00_UCDownloadFile1_Accept");
            if (elementById != null)
            {
                elementById.InvokeMember("click");
                Application.DoEvents();
            }

But a script error message box appear saying

"An error has occured in the script on this page. 
Error: The value of the property 'sysMT' is null or undefined, not a Function object.
Do you want to continue running script on this page? 
Yes     NO"

Not able to understand what I am missing in this. Did Parent url make some cookie which helps to download the file? Don’t know how to download that file and also download file link.

I am new to C# WebBrowser.

Update

I am able to remove a script error message box using

webBrowser2.ScriptErrorsSuppressed = true;

But not able to download all file which are their in sub links i.e.

If I get 3 links from a parent url, then I navigate to first link, click on Accept link and then a box appear asking for a action to RUN SAVE CANCEL. But I get this box only for third (last) link. How to overcome with this problem, I want to download all file from each links without any prompt which asking for RUN SAVE CANCEL. Directly SAVE a file.