####First - reset LaunchPad:
defaults write com.apple.dock ResetLaunchPad -bool true; killall Dock
####Second - rebuild the database:
rm ~/Library/Application\ Support/Dock/*.db; killall Dock
######tested with zsh 5.0.5 (x86_64-apple-darwin14.0) on Apple MacBook Pro (Late 2011) running OS X 10.10.3