MacOS – How to fix “Killed: 9” error in mac os

Both of those still work for me, but you do sometimes need to run defaults commands again after upgrading OS X. If you run the commands again, quit and reopen applications to apply the changes:

killall Dock Finder

(If you also want to enable selecting text in Quick Look windows shown from other applications than Finder, you can use defaults write -g QLEnableTextSelection -bool true instead of defaults write com.apple.finder QLEnableTextSelection -bool true.)

1. You can log out from the App Store after you click "Account" at the Quick Links sidebar (inside the "Feature" Tap)
2. You can log out and change the Apple ID inside the OS X settings
3. You need to log in with the Apple ID you bought the apps with
4. You can delete certain apps and keep the files. Like iPhoto keeps its Library inside the Pictures folder in your Home directory
5. You have to buy the Apps again if they cost money if you want to update them with your other Apple ID