I’ve recently done some major maintenance and upgrade to my Mac Book Pro, upgraded my OS to Snow Leopard and my iLife to the latest ’11 version. Like a child, I was enthusiastically launching my new iPhoto ’11 (version 9.1), couldn’t wait to get my hands on it, until I saw this stupid error message.

“iPhoto is unable to open this library. The library is not compatible with iPhoto.”

So how to solve this? Easy.

1. Go to Pictures > iPhoto Library > (Right Click) Select “Show Package Contents”

2. Select Database and double click on it.

3. Here you will see a list of files and folders you might not be familiar with. Don’t fret. Search for the “DataModelVersion.plist” file.

DataModelVersion.plist > (Right Click) Select Open With > Other…

4. Select “TextEdit.app” as the file editor.

5. Browse around the document and you will see isIPhotoLibrary.

The default value is “false”. Change it to “true” (as highlighted below).

Save file.

Voila! Problem solved!