Those of you Apple Macintosh users out there ready to jump onto the latest Mac OS X 10.6.5 update for Snow Leopard may want to first double-check that you’re not about to brick your shiny Mac. If you use PGP Whole Disk Encryption on your Mac, you’ll want to first decrypt your disks before installing the update.
It would seem that due to a miscommunication between Symantec (the folks who bought out PGP) and Apple, the Mac OS X 10.6.5 update contains a new EFI booter that doesn’t work with PGP’s WDE, rendering the machine unable to boot up. Possibly because Apple may have forgotten to put their latest EFI booter into the update’s beta test release. Or if they did, then possibly PGP just somehow forgot to actually test Apple’s Snow Leopard update?
Anyway, the solution is simple, if you haven’t applied the update yet. According to PGP, just decrypt your disks before installing the Snow Leopard upgrade and the new EFI booter has nothing to clash with. Then you can re-encrypt once the update is installed and your Mac safely rebooted to get back to the security you need. Of course that’s an unofficial solution.
If you wait long enough PGP/Symantec and Apple should officially sort this out. Assuming you don’t mind the wait.
If, however, you’ve already bricked your Mac and need a solution to bring it back to working order because you expected that any sane and competent company would have actually tested their software, well that’s fixable as well. And it’s not altogether too complicated either. Follow the instructions provided by PGP here. It involves downloading a CD image to burn yourself a recovery CD though, so you’ll likely need a working computer to perform it. But then, if you’re reading this, you probably have one of those handy. Oh, and you’d be needing a blank CD too I’d imagine since it requires burning a recovery CD and all.
Theoretically, if for some reason you can’t dig up a blank CD, there’s also been rumor that an approach similar to PGP’s fix can be used in which you put your bricked Mac into Target Disk Mode and then boot up with that other Mac that you still need, running PGP on that second Mac instead of booting off of the recovery CD. There are no explicit step-by-step instructions for this, but allegedly it’s really not all that different from PGP’s official fix so you should be able to sort it out.
Good luck and godspeed.