The testcase suddenly stop with an unknow errorr. with this error code

Hello I am trying to test an web application and sudenly I received this error. The web page is working and nothing had been trhow as an error. Please anyone help me?

https://community.smartbear.com/t5/forums/postpage/board-id/Functional_Web_TestingPossible reasons: 1. The application stopped responding. 2. The application was compiled incorrectly (see the Open Applications topic in the help system). 3. An error occurred in TestComplete/TestExecute. Technical information: 409 0x80020009 (Exception occurred.) . Tested object: Aliases.browser.pageHhGlobalHhub2.form.buttonLoginAs (Sys.Browser("iexplore").Page("https://XXXXXX/Security/EmulateUser").Panel(0).Panel(2).Panel(0).Panel(0).Panel(0).Panel(0).Panel(1).Panel("UsersGrid").Form(0).Panel(2).Panel(0).Table(0).Cell(10, 4).Panel(0).Button(0))