10.9.3 update failed to verify on three attempts, now what? I've tried to install the 10.9.3 update three times. Each time, the app store downloads, the machine reboots, and then up comes a dialog complaining that it could not verify the update. Upon clicking OK, it reboots and spends 7 minutes putting things back the way it found them.

Disk utility finds nothing to complain of, and there's plenty of space.

Machine is running 10.9.2, and it is a mid-2011 mac mini.

What do I do?
Try installing the combo updater instead:

http://support.apple.com/kb/DL1746