Apple released a point update for OS X Lion version 10.7.3 about 2 days ago but unfortunately it was bugged with CUI errors. Here’s how to fix it.
1. Download the combo installer from Apple support website.
2. Run the installer, restart into 10.7.3 and use Disk Utility. This will ensure that there are no broken permissions or other disk-related issues.
3. If you have an issue applying the combo installer, try booting your computer into Safe Mode (hold Shift during boot up until the desktop or login window appears).
4. If not resolved, you’ll need to find another Mac. Boot the problem system in Target Disk Mode (hold down the “T” key during startup). Connect to another Mac and run the combo installer on the other Mac against the problem machine’s boot drive by using Thunderbolt or FireWire.
Worst case scenarios, your Mac has been so badly affected by the update that the above will not work.
If you made a Time Machine backup before doing the update, restore it and apply the combo installer. That should fix it.
If All Fails…
1. Boot into the Recovery partition (hold down the Option key during boot).
2. Go ahead and Select “Disk Utility” from under Menu and mount the combo installer image file.
3. Choose “Terminal” under Menu and run the following:
“installer -pkg /Volumes/Mac\ OS\ X\ 10.7.3\ Update\ Combo/MacOSXUpdCombo10.7.3.pkg -target /Volumes/Macintosh\ HD”
Note: make sure to change the target to reflect the startup volume’s name.
4. Run “reboot”. If all goes well, these issues should be fixed by now!
Courtesy of 9to5Mac