To solve this problem:
- Make sure that the Expanding component in your parent file is the same size as the collapsed panel and positioned over the collapsed area. The Expanding component dictates in which direction the expand and collapse happen. It also acts as a mask.
For instance, if the unit size is 300x250 and it expands to 500x250, the size of the Expanding component in the parent Flash file should be 300x250. If the unit expands to the right, the Expanding component should be aligned to the left side of the stage.
- If you're using the API instead of the component, you can reposition the creative using Creative properties in the Studio Preview tab.
For more information on repositioning, see Creative positioning in Studio at the bottom of Expanding creatives without the Expanding component.