Pizzicato strings no longer work score wide, b-b-but.....

I have a score that I have been working on for a long time, and it's only now that pizzicato strings don't work. It'll work on new scores and other scores, but not this one. I'm leaning toward that the file is corrupt somehow. Is there something I can try before I trash this file and start again? I'll print it out beforehand so no worries (except for the listener)