OS X El Capitan: The Missing Manual

Minor Eccentric Behavior

All kinds of glitches may befall you, occasionally, in OS X. A menu doesn’t open when you click it. A program doesn’t open—it just bounces in the Dock a couple of times and then stops. A program freezes.

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 the Disk

An amazing number of mysterious glitches arise because of tiny file corruptions on your hard drive.

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 button, click Run, and then read an article while the Mac checks out your disk.

Second Resort: Look for an Update

If a program starts acting up immediately after you’ve installed OS X 10.11, chances are good that it has some minor incompatibility. Chances are also good that you’ll find an updated version on the company’s website.

Third Resort: Toss the Prefs File

A corrupted preference file can bewilder the program that depends on it.

Before you go on a dumpfest, however, take this simple test: Log in using a different account (perhaps a dummy account that you create just for testing purposes). Run the problem program. ...