Unexpected window message generating error and failing test

Hi 

If someone can point what is happening here and how this can be fixed 

I am testing desktop winform based app i am clicking a submenu item, on click a confirmation popup appears and yes button on confirmation popup  is clicked, that is it.

When I run my  function it works correctly AUT works correctly as expected yet Testcomplete logs as unexpected window error message 

I am struggling to find why does it show this message 

first it is not unexpected window, it is expected window second expected window is handled and closed , AUT works correctly and closes popup

yet it logs unexpected window could not be closed message 

On menu click there is no other window appearing except confirmation popup which is expected 

Here is my function 

function ReleaseMF()
{
OpenManifestForm();
LoadManifest("MFTransh1");
ClickManifestMenuRelease();
LogMessage( " after submenu release click")
PopupCloseWithTimeOut(popupQuestionCaption,btnYesPopup, 4000 );
LogMessage( " after popup has been closed");
} 

Thanks

Gagan