If you are experiencing difficulties with Lightroom 5 not opening and Aperture not exporting images on OSX 10.9 here’s the fix if you have your Catalogs and Projects on external drives. Because of the new security measures / protocols you need to ensure that your external drives have read and write permissions for all users. After a lengthy discussion with a tech genius friend of mine this was the solution he offered and everything is fine now. Go to it.