The most frequent cause for this problem is that you cannot add an image as an alternate background layer in addition to the background layer and then add motion. Encore replaces the bottom-most layer with the motion, and then you still see the higher layer image which covers up the motion. This issue also results if the layer named "background" is not at the bottom of the stack. Or if you add a button that has a layer that covers the entire area.
Also, the visibility of the bottom layer must be "on."
If you are not experienced, work with a template other than "blank." For example, in the Library, select the Wedding set, and then the menu Montage Wide It has a motion asset.
