I checked the article and it says "Tab Layout with Dynamic Container is configured with Size height to content. When this option is checked, the modal dialog is visible at the center of the available total height of the harness."
When I uncheck the check box , while rendering I see a blank screen in ie and a very very small screen in chrome.
"Render in HTML5" is already checked in the app
Tried even changing the document mode but it's not helping.