iPhoto
I'm running a iMac G5, High Sierra 10.13.6. I'm trying to recover a 2013 iPhoto library from an external hard drive. I have installed iPhoto without problems from 2013 App Store purchases. I have also, as directed, installed the iPhoto Library Upgrader and run it on the specific library file I want. According to the 2016 Upgrader instructions from Apple, dated 2016, I should then be able to access the library using iPhoto.
However, when I try to load the file in iPhoto, I continually get the same "library must be upgraded message." I know the library files are too old to migrate to Photos, but I'm not trying to do that. Getting access through iPhoto is all I need. Suggestions welcome.
iMac with Retina 5K display, macOS 10.13