WebpageTest on safari shows blank page

I am using safari-5.1.7 in windows 2008r2 server. While running the tests, safari open blank page instead of redirecting to the url

I have tried installing the extension that comes with the agent, still facing the problem. What could be the issue?

When you open safari manually, does it try to load http://127.0.0.1:8080/… something like 10 seconds after starting up? If not, then the extension isn’t installed or working correctly.