Q: iPhoto up-date not completing

I have up-graded to Mountain Lion (I know, I'm behind the times, I have an antique iMac that won't support El Capitan). The problem is that I can't seem to up-date my version of iPhotos (currently iPhotos 11 v 9.2.3). The up-date starts in the App Store, but disconnects just over halfway through (error code 102, I think). Can anyone help?!