I have run the Upgrader Tool against my library ten times and it's still not working. Any suggestions?
MacBook Pro, OS X El Capitan (10.11.3)
Figured out my problem.
I needed to run the Upgrader from the Utilities menu first. That fixed my issue.
Are you trying to open an iPhoto library in Photos? You need the upgrader only, if your iPhoto Library is an iPhoto 7.1.2 library or older. Is your iPhoto version that old?
What happens, when you try to open your iPhoto Library in Photos? Any error messages? What does not work?
iPhoto Library Upgrader
