Which version of iPhoto are you using? and which MacOS X version?
Does it happen only for certain slideshows or all slideshows?
If you are using iPhoto 9.4.5 or an earlier version, iPhoto will crash, whenever you are trying to use maps. It is no longer supported.
See:
The early iPhoto '11 versions started to crash for many users all of a sudden last month.
There is a problem with the Places feature, because the Google maps are no longer supported.
See Huxly647's solution:
Huxly647Nov 20, 2015 12:05 AM
Re: iPhoto crashes after opening repeatedlyin response to carvermonHelpful
I found a fix that works for me..
1. goto /Applications/iPhoto.app/Contents/Resources
2. delete the files ' googlemap.html ' and googlesearch.html
Iphoto no longer crashes, places doesn't work but it doesn't bother me too much.
Let me know if it works for you guys...
Removing the two files ' googlemap.html ' and googlesearch.html from iPhoto's application bundle prevents the javascript inside from being executed and causing the crash. Going offline does obviously do the same. So it is pretty clear, that something happened on Google's end.
Don't try this fix without making a copy of the iPhoto application before you try to remove the two files from the application bundle.