If you were to list all the Windows features Macintosh users have wished for, you’d never see the “Blue Screen Of Death” among them. Which is why it’s such a shock when restarting an OS X machine to see the Apple logo, followed immediately by a frozen field of bright blue. Unlike Windows, there’s not even any diagnostic information to accompany the colorful rebuke.

This issue occurs most frequently right after Software Update has run on Leopard. It’s most often caused by a corrupt dynamic loader cache, a feature which replaced “application prebinding” in OS X 10.5 and tells the system where to find available shared libraries. Without a roadmap to these libraries, the computer can’t boot properly.

If the affected system is running 10.5.6, you can remedy this problem by booting with the “Shift” key held, triggering a Safe Boot sequence and deleting the damaged cache files. If you’re running an earlier version of Leopard, Safe Boot won’t remove the caches, so you’ll have to boot the machine from a DVD or external drive and remove the files manually from /var/db/dyld/ instead.

Once the cache files have been removed, the machine should restart normally.