A bug with the recent OS X 10.9.3 update causes the Users folder to no longer be available in Finder and some apps. There are a few ways to fix this, but the simplest one that persists after reboot is to create an AppleScript and have it load on login.
tell application "Terminal"This video will walk you through a couple fixes including a very simple fix that will work after you reboot.
do shell script "chflags nohidden /Users" password "yourLoginPassword" with administrator privileges
The more complicated fix that I briefly showed in the video is to:
start your computer with Alt + CMD + P + R in order to do a PRAM reset.
Then start your computer with CMD + R for recovery partition boot
Launch Disk Utility and repair permissions. Quit Disk Utility and open Terminal (Utilities -> Terminal) and type :
cd /Volumes/Macintosh\ HD (or the name of your partition)
chmod 755 Users
chmod 755 Users/Shared
chflags nohidden Users
chflags nohidden Users/Shared
A method I don't recommend for now.
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