First Try this: launch iPhoto with the Option key held down and create a new, test library. Import some photos and check to see if the same problem persists. If it doesn't then your original library is the culprit.
If that's the case make a temporary, backup copy of your library if you don't already have one (Control-click on the library and select Duplicate from the contextual menu) and apply the two fixes below in order as needed:
Launch iPhoto with the Command+Option keys held down and rebuild the library.
Since only one option can be run at a time start with Option #3, followed by #4 and then #1 as needed.
Using iPhoto Library Manager to Rebuild Your iPhoto Library
1 - download iPhoto Library Manager and launch.
2 - click on the Add Library button, navigate to your Home/Pictures folder and select your iPhoto Library folder.
3 - Now that the library is listed in the left hand pane of iPLM, click on your library and go to the File ➙ Rebuild Library menu option.
4 - In the next window name the new library and select the location you want it to be placed.
5 - Click on the Create button.
Note: This creates a new library based on the LIbraryData.xml file in the library and will recover Events, Albums, keywords, titles and comments. However, books, calendars, cards and slideshows will be lost. The original library will be left untouched for further attempts at fixing the problem or in case the rebuilt library is not satisfactory.
I have been trying to catch up my iPhoto and video library and have run into several glitches. Whenever I come here for an answer, I get Old Toad's advice, which has solved a lot of problems for me. Thanks!
A number of photos are on my desktop, most of which are jpegs, and amazingly, even some pdf files! I have been dragging them into iPhoto, but eventually got the same out of space message. Tried to delete, get rid of stuff, got rid of 20 GB of stuff, still same message. Didn't believe it, came here for help, and find that, as usual, Old Toad has a thorough answer.
But sometimes I find that my mac is out of practice, and the first few times I do something it doesn't work, so I tried the easy answer first, hoping to sort of kick-start the process. Used preview to change one single photo from a jpg to a tiff and dragged it into iPhoto. It was a much bigger file, but iPhoto just gobbled it right up and displayed it properly. Then guess what? They are all importing properly, jpegs, tiffs, pdfs, even movies! I am just dragging them in as usual.
This might be a magic shortcut others can try; it's simple enough. If it quits working I'll try Old Toad's long and probably proper method. Good luck!
MacBook Pro 2.4 GHz intel Core 2 Duo, 4 GB Memory, OS X v. 10.9.1
I have tried all this and the iPhoto Library First Aid does not launch. I tried holding the Option and Command keys a long time, still no luck. When I tried the iPhoto Library Manager fix, it gave me an error message along the lines that my version of Aperture was not the correct one and I could not do the rebuild library.
Any other suggestions?
Starting over from scratch with new library
Start over with a new library and import the Originals (iPhoto 09 and earlier) or the Masters (iPhoto 11) folder from your original library as follows:
1. Open the library package like this.
2. Launch iPhoto with the Option key held down and, when asked, select the option to create a new library.
3. Drag the subfolders of the Originals (iPhoto 09 and earlier) or the Masters (iPhoto 11) folder from the open iPhoto Library package into the open iPhoto window a few at a time.
This will create a new library with the same Events (but not necessarily the same Event names) as the original library but will not keep the metadata, albums, books slideshows and other projects.
Note: your current library will be left untouched for further attempts at a fix if so desired.