After update, background turned black, the dock is missing As you can see it, after updating the commandline tools for xcode, the background turned black and the dock is missing



the OS is macOS Sierra 10.12.4(16E195)

How can I fix it?
On rare occasions, I have had to go nuclear and clean out specific preference files:

rm ~/Library/Preferences/com.apple.finder.plist

One might argue that you should back it up first. In that light, I suggest simply moving it out of the way and force-quitting Finder.

cd ~/Library/Preferences
mv com.apple.finder.plist com.apple.finder.plist-orig