Mac OS X Lion: The Missing Manual

Minor Eccentric Behavior

All kinds of glitches may befall you, occasionally, in Mac OS X. Your desktop picture doesn’t change when you change it in System Preferences. A menulet doesn’t open when you click it. A program won’t open—it just bounces in the Dock a couple of times and then stops.

When a single program is acting up like this, but quitting and restarting it does no good, try the following steps, in the following sequence.

First Resort: Repair Permissions

An amazing number of mysterious glitches arise because the permissions of either that item or something in your System folder—that is, the complex mesh of interconnected Unix permissions described in Chapter 12—have become muddled.

When something doesn’t seem to be working right, therefore, open your Applications→Utilities folder and open Disk Utility. Proceed as shown in Figure B-1.

This is a really, really great trick to know.

Figure B-1. Click your hard drive’s name in the left-side list, click the First Aid tab, click Repair Disk Permissions, and then read an article while the Mac checks out your disk. If the program finds anything amiss, you’ll see messages like these. Among the text, you may recognize some Unix shorthand for read, write, and execute privileges (Chapter 16).

Second Resort: Look for an Update

If a program starts acting up immediately after you’ve installed Mac OS X 10.7, chances are good that it has some minor ...