Mavericks: notifications no longer displaying I recently upgraded to Mavericks (download from app store).

Before this upgrade, I could click on the the notifications UI element at the very top-right of the display; this would cause the whole screen to shift to the left and display a list of notifications:



Now, after the upgrade, this UI element simply turns blue during the mousedown, and nothing else happens.

Are there any known fixes or workarounds to this?



I should add I am experiencing a similar but not identical issue with the spotlight UI element:



When I click on this one, I just get a "bonk" sound and no spotlight search bar.  However I can use spotlight without problems from finder windows, etc.



I don't know, but I'm guessing these two issues may be related simply because of their proximity on the screen.

Other taskbar UI elements appear to be working normally.
First, check your settings in System Preferences > Notifications. You may have Do Not Disturb enabled.
  
  For com.apple.notificationcenterui.plist. It's located in your user library, not root level where you may be looking.
  
  Open the Finder. From the Finder menu bar click Go > Go to Folder
  
  Type or copy paste the following:
  
  ~/Library/Preferences/com.apple.notificationcenterui.plist
  
  Click Go then move the com.apple.notificationcenterui.plist file to the Trash.
  
  Restart your Mac.
  
  I can't locate the com.apple.soagent.plist in either user or root.
  
  If deleting the com.apple.notificationui.plist file did not help, reinstall OS X >  OS X Mavericks: Reinstall OS X
  
  That will reinstall any missing system files required for the Notification center.


From https://discussions.apple.com/message/25351691#25351691