Hi

Photostory like many Magix programs does not have a Close option on the File menu.

Are you wanting to close the current slideshow and then start a new one?

If you wish to start a new slideshow click File, New - you may be asked if you want to save the current slideshow - click Yes the current slideshow will close and a new empty slideshow will start.

Or

Do you mean you cannot close the slideshow to exit the program? 

There is no close - exit the program and again it may ask you to save any changes - click Yes and the slideshow and program will close

Or

Do you mean you cannot close the program at all?  In which case are you getting any messages?

John