iPhoto freezes while uploading photo calendars for printing
I have a MacBookPro OS X 10.6.8 and have not upgraded to Yosemite, nor have I upgraded the iPhoto application from iPhoto '11 9.2.3 (though I've been prompted to). I have tried for the past several days to upload calendars to Apple to be printed and mailed. I've never had a problem with this before, but now, iPhoto keeps freezing up after assembling the calendar and beginning to upload it. This happens for each of several calendars I have prepared for various family members, so it's not specific to one calendar. Each time, I've been forced to restart the computer, but encounter the same problem when I try again to order the calendar.
How can I fix this problem?
MacBook Pro (13-inch Mid 2010), Mac OS X (10.6.8)