Cannot copy iPhoto library from network…: Apple Support Communities. wizdomonwheels discovered the solution.

First off, try dragging the file to your desktop or somewhere other than your Photos folder to make sure that it’s not trying to overwrite an existing file.

If that doesn’t work, it’s possible that the file is larger than 2GB and if your NAS is not formatted for the Mac it may have trouble copying.

Either way, right click (or control click) on the iPhoto Library and choose “Show Package Contents”.

Create a new folder wherever you want on your computer called iPhoto Library Copy (you can name it anything you want).

Slowly drag the contents from inside the old iPhoto Library into the new folder you’ve created.  Since it handles the files like a normal folder system, it should give errors on whatever may be corrupted, anything corrupted you can skip.

Once it’s done copying, go to file–> get info, and go down to permissions, unlock it, then make sure you have read/write access to the files.  Click the Cog and choose “Apply to Enclosed Items”.

Once you’ve got everything copied locally, launch iPhoto with the Option key down, and choose to create a new iPhoto Library.  Once a new one is created, quit iPhoto, show contents of the iPhoto library you just created, and drag copy your old contents into the new library.

Open iPhoto again and see how it does!