If you installed Thunderbolt Software 1.2, (in its characteristic understated manner): “You may notice your Mac becomes unresponsive on startup.” Oops. After discovering the problem, Apple promptly withdrew the update, citing the cause as a compatibility problem with a previous “Thunderbolt update applied by some customers.” If you find yourself in this boat, the solution is to reinstall OS X, ideally and most simply via . Meanwhile, Apple has released . The new update presumably does not contain the startup failure bug.

After installing for the MacBook Pro with Retina Display, that the Trackpad may become (here’s that word again) “unresponsive.” In this case, this can happen if your Mac goes to sleep in the middle of the update installation. Such untimely naps are never recommended for any update, and you would think Apple’s Installer would prevent this from occurring. Apparently not. If this does happen to you, the solution is simply to reinstall the update. Since your Trackpad is temporarily out of commission, you’ll want to attach a mouse or other external input device to carry out the re-install. If none is available, the cited Apple article gives a 12-step procedure for how you can accomplish the desired goal entirely from the keyboard.