I know this is an old thread but I just want to chip in to this. I got this exact problem trying to put anything into a QScrollBar in designer and they just don't work because of this stupid dummy "scrollAreaWidgetContents" that was auto created. It cannot be modified or deleted. The only workaround I found is to do everything in the main cpp, creating the image label and adding it to the QScrollArea object, skipping the scrollAreaWidgetContents, which completely took away the convenience of using the designer.