iPhoto says my photo library is unreadable?!?

When i open my iphoto a notification comes up :

but i have not changed even used iphoto for about a year now.

I have tried holding down option + command keys and this menu comes up:

i have tried every single option however it just comes back with the original message. I was wondering if there was any way to reinstall iphoto or some how reset iphoto.

i am currently using 10.8.2 mountain lion and is running on a macbook pro late 2011 edition