Recent items menus have stopped working on my iMac
For me, this partially fixed things:


Close all open apps.
Move ~/Library/Preferences/com.apple.recentitems.plist (and ~/Library/Preferences/com.apple.recentitems.plist.lockfile if it exists) to a backup directory.
Reboot.


In my case this fixed the recent items lists under the File menu in each app and the Apple menu. But the context menus on Dock icons still do not update.