localhost:20980 vs localhost:20980/Default.aspx

Question

Listview Insert and Edit buttons work on localhost:20980/Default.aspx but does not work on localhost:20980. Same happens on production. What makes the difference between the two and what disallows buttons to work with localhost:20980?

Breakpoint inside btnInitInsert_Click() method stops the execution on localhost:20980/Default.aspx, but does not on localhost:20980

Answer 1

This worked. From

public void Page_PreRender(object sender, EventArgs e)
{
        if (string.IsNullOrEmpty(this.Page.Form.Action))
            this.Page.Form.Action = "Default.aspx";
 }