. . . . I press the play button, I get a message that the playback device is not activated . . . .
We need more information:
What is the full name and version number of the program as found under Help, About
What you have done and are trying to do?
For example:
Is the error occurring within the Photostory when you try to play the project you have created?
or
Have you created and exported a slideshow and when you play it you get the Device error message?
If neither of the above can you post a screenshot of the error message, and your computer specification - see this topic for what is required and please quote the full make and name of the Processor and Graphics card(s) / chipset make.