"Windows Security" dialog not recognized during playback

The test gets stuck, because it waits for the page to load completely before entering the credentials. But the page finishes loading only after it receives the credentials - which results in a lock.

To avoid the issue, you need to navigate to the page without waiting for it to load. For example, replace this line:

Browsers.Items(btIExplorer).Run("http://www.test.com");

with these:

var browserInfo = Browsers.Item(btIExplorer);
browserInfo.RunOptions = "http://www.test.com"; // your URL
browserInfo.Run();