Q: So many problems with El Capitan

Please read this whole message before doing anything.

This procedure is a test, not a solution. Don’t be disappointed when you find that nothing has changed after you complete it.

Step 1

The purpose of this step is to determine whether the problem is localized to your user account.

Enable guest logins* and log in as Guest. Don't use the Safari-only “Guest User” login created by “Find My Mac.”

While logged in as Guest, you won’t have access to any of your documents or settings. Applications will behave as if you were running them for the first time. Don’t be alarmed by this behavior; it’s normal. If you need any passwords or other personal data in order to complete the test, memorize, print, or write them down before you begin.

Test while logged in as Guest. Same problem?

After testing, log out of the guest account and, in your own account, disable it if you wish. Any files you created in the guest account will be deleted automatically when you log out of it.

*Note: If you’ve activated “Find My Mac” or FileVault, then you can’t enable the Guest account. The “Guest User” login created by “Find My Mac” is not the same. Create a new account in which to test, and delete it, including its home folder, after testing.

Step 2

The purpose of this step is to determine whether the problem is caused by third-party system modifications that load automatically at startup or login, by a peripheral device, by a font conflict, or by corruption of the file system or of certain system caches.

Please take this step regardless of the results of Step 1.

Disconnect all wired peripherals except those needed for the test, and remove all aftermarket expansion cards, if applicable. Start up in safe mode and log in to the account with the problem.

Note: If FileVault is enabled in OS X 10.9 or earlier, or if a firmware password is set, or if the startup volume is a software RAID, you can’t do this. Ask for further instructions.

Safe mode is much slower to start up and run than normal, with limited graphics performance, and some things won’t work at all, including sound output and Wi-Fi on certain models. The next normal startup may also be somewhat slow.

The login screen appears even if you usually log in automatically. You must know your login password in order to log in. If you’ve forgotten the password, you will need to reset it before you begin.

Test while in safe mode. Same problem?

After testing, restart as usual (not in safe mode) and verify that you still have the problem. Post the results of Steps 1 and 2.

1. This procedure is a diagnostic test. It changes nothing, for better or worse, and therefore will not, in itself, solve the problem. But with the aid of the test results, the solution may take a few minutes, instead of hours or days.

The test works on OS X 10.7 ("Lion") and later. I don't recommend running it on older versions of OS X. It will do no harm, but it won't do much good either.

Don't be put off by the complexity of these instructions. The process is much less complicated than the description. You do harder tasks with the computer all the time.

2. If you don't already have a current backup, back up all data before doing anything else. The backup is necessary on general principle, not because of anything in the test procedure. Backup is always a must, and when you're having any kind of trouble with the computer, you may be at higher than usual risk of losing data, whether you follow these instructions or not.

There are ways to back up a computer that isn't fully functional. Ask if you need guidance.

3. Below are instructions to run a UNIX shell script, a type of program. As I wrote above, it changes nothing. It doesn't send or receive any data on the network. All it does is to generate a human-readable report on the state of the computer. That report goes nowhere unless you choose to share it. If you prefer, you can act on it yourself without disclosing the contents to me or anyone else.

You should be wondering whether you can believe me, and whether it's safe to run a program at the behest of a stranger. In general, no, it's not safe and I don't encourage it.

In this case, however, there are ways for you to decide whether the program is safe without having to trust me. First, you can read it. Unlike an application that you download and click to run, it's transparent, so anyone with the requisite skill can verify what it does.

You may not be able to understand the script yourself. But variations of it have been posted on this website thousands of times over a period of years. The site is hosted by Apple, which does not allow it to be used to distribute harmful software. Any one of the millions of registered users could have read the script and raised the alarm if it was harmful. Then I would not be here now and you would not be reading this message. See, for example, this discussion.

Another indication that the test is safe can be found in this thread, and this one, for example, where the comment in which I suggested it was recommended by one of the Apple Community Specialists, as explained here.

Nevertheless, if you can't satisfy yourself that these instructions are safe, don't follow them. Ask for other options.

4. Here's a general summary of what you need to do, if you choose to proceed:

☞ Copy a particular line of text to the Clipboard.

☞ Paste into the window of another application.

☞ Wait for the test to run. It usually takes a few minutes.

☞ Paste the results, which will have been copied automatically, back into a reply on this page.

These are not specific instructions; just an overview. The details are in parts 7 and 8 of this comment. The sequence is: copy, paste, wait, paste again. You don't need to copy a second time.

5. Try to test under conditions that reproduce the problem, as far as possible. For example, if the computer is intermittently slow, run the test during a slowdown.

You may have started up in safe mode. If the system is now in safe mode and works well enough in normal mode to run the test, restart as usual before running it. If you can only test in safe mode, do that.

6. If you have more than one user, and only one user is affected by the problem,, and the affected user is not an administrator, then please run the test twice: once while logged in as the affected user, and once as an administrator. The results may be different. The user that is created automatically on a new computer when you start it for the first time is an administrator. If you can't log in as an administrator, test as the affected user. Most personal Macs have only one user, and in that case this section doesn’t apply. Don't log in as root.

7. Load this linked web page (on the website "Pastebin.") The title of the page is "Diagnostic Test." Below the title is a text box headed by three small icons. The one on the right represents a clipboard. Click that icon to select the text, then copy it to the Clipboard on your computer by pressing the key combination command-C.

If the text doesn't highlight when you click the icon, select it by triple-clicking anywhere inside the box. Don't select the whole page, just the text in the box.

8. Launch the built-in Terminal application in any of the following ways:

☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)

☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.

☞ Open LaunchPad and start typing the name.

Click anywhere in the Terminal window to activate it. Paste from the Clipboard into the window by pressing command-V, then press return. The text you pasted should vanish immediately.

9. If you see an error message in the Terminal window such as "Syntax error" or "Event not found," enter

exec bash

and press return. Then paste the script again.

10. If you're logged in as an administrator, you'll be prompted for your login password. Nothing will be displayed when you type it. You will not see the usual dots in place of typed characters. Make sure caps lock is off. Type carefully and then press return. You may get a one-time warning to be careful. If you make three failed attempts to enter the password, the test will run anyway, but it will produce less information. If you don't know the password, or if you prefer not to enter it, just press return three times at the password prompt. Again, the script will still run.

If the test is taking much longer than usual to run because the computer is very slow, you might be prompted for your password a second time. The authorization that you grant by entering it expires automatically after five minutes.

If you're not logged in as an administrator, you won't be prompted for a password. The test will still run. It just won't do anything that requires administrator privileges.

11. The test may take a few minutes to run, depending on how many files you have and the speed of the computer. A computer that's abnormally slow may take longer to run the test. While it's running, a series of lines will appear in the Terminal window like this:

[Process started]

        Part 1 of 4 done at … sec
        …
        Part 4 of 4 done at … sec

        The test results are on the Clipboard.

        Please close this window.

[Process completed]

The intervals between parts won't be exactly equal, but they give a rough indication of progress.

Wait for the final message "Process completed" to appear. If you don't see it within about 15 minutes, the test probably won't complete in a reasonable time. In that case, press the key combination control-C or command-period to stop it. Then go to the next step. You'll have incomplete results, but still something. If you close the Terminal window while the test is still running, the partial results won't be saved and you'll have to start over.

12. When the test is complete, or if you stopped it because it was taking too long, quit Terminal. The results will have been saved to the Clipboard automatically. They are not shown in the Terminal window. Please don't copy anything from there. All you have to do is start a reply to this comment and then paste by pressing command-V again.

At the top of the results, there will be a line that begins with the words "Start time." If you don't see that, but instead see a mass of gibberish, you didn't wait for the "Process completed" message to appear in the Terminal window. Please wait for it and try again.

If any private information, such as your name or email address, appears in the results, anonymize it before posting. Usually that won't be necessary.

13. When you post the results, you might see an error message on the web page: "You have included content in your post that is not permitted," or "The message contains invalid characters." That's a bug in the software that runs this website. Please post the test results on Pastebin, then post a link here to the page you created.

If you have an account on Pastebin, please don't select Private from the Paste Exposure menu on the page, because then no one but you will be able to see it.

14. This is a public forum, and others may give you advice based on the results of the test. They speak for themselves, not for me. The test itself is harmless, but whatever else you're told to do may not be. For others who choose to run it, I don't recommend that you post the test results on this website unless I asked you to.

______________________________________________________________

Copyright © 2014, 2015 by Linc Davis. As the sole author of this work (including the referenced "Diagnostic Test"), I reserve all rights to it except as provided in the Use Agreement for the Apple Support Communities website ("ASC"). Readers of ASC may copy it for their own personal use. Neither the whole nor any part may be redistributed.

A

Follow these instructions to display the machine's serial number. If the number is missing or invalid according to this web form, take the machine to an Apple Store or other authorized service center to have the problem corrected.

B

Please sign out of iCloud in its preference pane and see whether there's any change. No data will be removed from the servers, and you can retrieve it by signing back in. That said, you should always have a current archive of the data for safety's sake, even if you don't sign out.

If you use iCloud Keychain, when you sign back in to iCloud follow one of the procedures described in this support article to set it up on an additional device.

C

Update or (preferably) remove the Seagate drive-management software.

Any third-party software that doesn't install from the App Store or by drag-and-drop into the Applications folder, and uninstall by drag-and-drop to the Trash, is a system modification.

Whenever you remove system modifications, they must be removed completely, and the only way to do that is to use the uninstallation tool, if any, provided by the developers, or to follow their instructions. If the software has been incompletely removed, you may have to re-download or even reinstall it in order to finish the job.

I never install system modifications myself, and except as stated in this comment, I don't know how to uninstall them. You'll have to do your own research to find that information.

Here are some general guidelines to get you started. Suppose you want to remove something called “BrickMyMac” (a hypothetical example.) First, consult the product's Help menu, if there is one, for instructions. Finding none there, look on the developer's website, say www.brickmymac.com. (That may not be the actual name of the site; if necessary, search the Web for the product name.) If you don’t find anything on the website or in your search, contact the developer. While you're waiting for a response, download BrickMyMac.dmg and open it. There may be an application in there such as “Uninstall BrickMyMac.” If not, open “BrickMyMac.pkg” and look for an Uninstall button. The uninstaller might also be accessed by clicking the Customize button, if there is one.

Back up all data before making any changes.

You will generally have to restart the computer in order to complete an uninstallation. Until you do that, there may be no effect, or unpredictable effects.

If you can’t remove software in any other way, you’ll have to erase and install OS X. Never install any third-party software unless you're sure you know how to uninstall it; otherwise you may create problems that are very hard to solve.

Trying to remove complex system modifications by hunting for files by name often will not work and may make the problem worse. The same goes for "utilities" such as "AppCleaner" and the like that purport to remove software.

D

Remove "Memory Monitor" or "Memory Diag," which is at best useless.

E

When you ran the test, the battery was low on charge. If the charge always reads low in the Energy Saver preference pane or in the menu bar, the battery may need to be replaced, or there may be some other hardware problem.