First, you need to select and "hide" all objects on the page within the content area. Then try to select area beside the content field. If there is something - you will catch it. Then set coordinate x for caught object (or group of objects) to 300 and press Enter. The object (or group of objects) will be moved to the visible part of the content area. Then you press "show all objects" and arrange them as you wish. Please, see the attached screenshots.