My iPhoto library was corrupted and even the Apple’s build in tools for repairing the database and rebuilding thumbnails did not longer work. Any attempt to use these tools lead to a crash. Working with the photos was also increasingly difficult, since iPhoto would frequently crash. The library contains more than 33.000 photos spanning 12 years. I was not prepared to give them up.
I have been using iPhoto Library Manager for some time for quickly moving between libraries but today it became my true champion. The software has a tool to recover corrupted libraries. But it works differently from Apple’s approach. It starts with a fresh clean library and imports all the photos, including their meta data, such as location, faces, date. It also manages to rebuild albums and folders. After nearly 20 hours of processing, my new library was fully functional. No more crashes or missing thumbs.
The culprit turned out to be the QuickTime plugin Perian. Once I uninstalled it, iPhoto worked without crashing. It is a pity, since Perian is so useful.