How disable "File Download - Security Warning" popups in webbrowser control

I have a WebBrowser control in my application. Whenever there is an error condition occurs, like a bad request(400) or page not found(404) etc.. my application navigates to "Navigation to the webpage was cancelled" page. On the same time, a popup dialog(File Download - Security warning) is appears in that background. I want to block this popup dialog and needs a smooth navigation. It shows that the file is from ieframe.dll

I have tried _webBrowser.ScriptErrorsSuppressed = true;

But it didn't worked. The popup was still there. The image is attached below.


Can anyone please help me to resolve this issue?

Thanks in Advance.