"unable to write to library" iPhoto library

Hi natalieramram,

Thanks for participating in the Apple Support Communities.

If you receive an "unable to write to library" message when using iPhoto, I recommend trying to repair the library permissions.

Before troubleshooting, it is always a good idea to back up your iPhoto library if you haven't already. See this link for the steps to back up your Mac using Time Machine:

OS X Yosemite: Back up your files with Time Machine

Next, you can use the steps in this article to access the "Rebuild iPhoto library" menu and choose the "repair iPhoto library file permissions" option:

iPhoto 6 and later: Rebuilding the iPhoto library - Apple Support

To rebuild the iPhoto library:

1. Quit iPhoto if it is open.
   
2. Hold down the Command and Option keys on the keyboard.
   
3. Open iPhoto.
   
4. Keep the keys held down until you are prompted to rebuild the library.
   
5. A dialog will appear with rebuild options. Select the options you want to use.
   
6. Click Rebuild to begin the rebuild process. This may take a few minutes to complete.

All the best,

Jeremy