That effect is part of the Frischluft Lenscare package:
http://www.frischluft.com/lenscare/
Your options are either:
1) Purchase the plug-in. Perhaps if the person who supplied you with the file has a vested interested in you being able to use this plug-in they will help you purchase it.
2) Replace all instances of FL Out of Focus with a similar effect like Camera Lens Blur in CS5.5+. The feature sets are not exactly the same and the results will be different, but it may get you "close enough." You'd also have to do all of these replacements manually. I'd recommend saving a copy of the project file before doing this.
Darby Edelen
