run the following command (based on: https://apple.stackexchange.com/questions/342443/dock-not-restarting-after-killall-dock)
killall System\ Preferences > /dev/null 2>&1 && rm ~/Library/Application\ Support/Dock/desktoppicture.db && killall Dockrun the following command (based on: https://apple.stackexchange.com/questions/342443/dock-not-restarting-after-killall-dock)
killall System\ Preferences > /dev/null 2>&1 && rm ~/Library/Application\ Support/Dock/desktoppicture.db && killall Dock