Where are you looking?
I installed version 15 yesterday and found several theme thumbnails under Create > Instant Movie.
To conserve space on your computer they are not normally downloaded until you want to use one. Optionally, they can be all downloaded at once.
When I go to create instant movie, there is just 1 theme. I can not see any button to download more.
You installed the program and all the themes automatically installed?
Does anyone know if there is a button to press to download the missing ones?
At the top there is a dropdown menu: show all.
I just installed 15 and there is only ONE movie theme. Still looking for answers.
Well that was stupid.
Click the Tools menu then Movie Menu - in the drop down you will now have 7 or 8 categories to choose from.
Apparently creating and instant movie or exporting to disk (and then answering yes to the question about adding menus) will only get one category and one option. Stupid.