Unable to identify element in already opened browser

I have an already opened browser window.And I want to identify elemnet in that window.

WebUI.verifyElementPresent is not working,but when I am using this in my previuos test case where I have openbed browser,it is working.

 

In my second test case,I do not want to open browser agin,it is already in the required page

I saw the error message from reports folder that root cause is browser not opened.And same statement for verification of element when I put in first test case,where I opened the browser instance is working fine

Can you show me its error message which you indicates from ‘it’s not working’ statement?