When I changed from my old macbook to my new macbook air the photo library was corrupted. I have all the thumbnail pictures in the proper events, but when I open them they are small. If I expand them the pixels begin to show. I tried to move the library from my old macbook to a external hard drive. I thought I was successful but when I try to open a picture from the thumbnail, I get a grey exclamation point. Any help would be appreciated.