I get this message when I try to get updates for Logic Pro X and iMovie. I have my /Users directory pointing (symbolic link) to /Volumes/DATA/Users, which is a SSD drive. I never received this message before when downloading updates and I was wondering if someone has run into the same problem recently. Googling this error points to bugs with El Capitan and many have suggested to recreate the /Users/Shared directory because of permissions issues (which doesn't seem to be a problem on my end). Any help with this issue will be GREATLY appreciated. Thanks.