The issue at hand may simply be caused by a bad preference setting or user-specific data file. With proper isolation, you can avoid time-consuming and inappropriate troubleshooting methods.
About user accounts and troubleshooting
When you first set up your Mac, you go through the Setup Assistant to create a default administrator account, configured to automatically log in to the computer. You can later add additional user accounts or turn off automatic login using System Preferences. Each account has its own desktop, user-specific preference settings, and account-specific folders (described below).
In OS X, almost all the changes you make to settings for apps, as well as other data you create and modify, are stored in your user account's Home folder ( /Users/your_account_name, also represented as ~/ ).
Here are some of the things that are usually stored in a user account's Home folder:
- Files on the desktop.
- Files in Documents, Downloads, Movies, Music, Pictures, Public and Sites folders.
- Any custom settings created for apps such as Mail, Safari, Calendar or iCal, Finder, System Preferences, and other app settings you have modified, as well as third-party software settings.
- Mail data, iTunes data (music, books, movies, apps), Contacts or Address Book contacts and groups, Safari bookmarks, Calendar or iCal calendars and events, iPhoto photos and movies, iMovie projects, third-party application data, and most files that you interact with.
When to troubleshoot with another user account
Testing with a new user isn't usually the first thing to do when isolating an issue, but should be tried before steps such as reinstalling apps, reinstalling OS X, or erasing the startup disk.
If an issue occurs only when logged in to a specific user account, reinstalling OS X or apps are not useful troubleshooting steps. If an issue doesn't happen when logged in to a new user account, then you know OS X and your installed applications are working as expected.
Troubleshoot with a test user account if the following are true
- It is unclear whether or not the issue is limited to just one user account.
- The issue occurs after logging in a user account (that is, after your desktop appears).
- There is an Internet account-based issue in which it is unclear whether or not the issue is occurring just with your user or with the account itself. For example, local issues with iCloud, Exchange, third-party email, calendaring, chat, and synchronization services. Note: For issues that only occur in a web browser, it's often best to test in multiple web browsers and with multiple websites, and then perform browser troubleshooting as necessary. If the issue occurs with multiple browsers or websites, consider testing with a different user account.
Don't troubleshoot with a test user for the following
- Any issue that happens before the Login window appears.
- Physically damaged equipment, disconnected cables, etc.
- Issues that affect multiple computers.
Note: An exception to this might be if you are using copied, synchronized or otherwise duplicated preferences or settings on multiple computers. For example, if you have migrated or restored the same user account to multiple computers, have manually copied settings between computers, and/or are using iCloud or another service to sync preferences or keychains between computers.
- Internet account issues that occur with service-provider web applications, such as issues that are due to a site's service outage. For example, when one website is unavailable due to it being down or temporarily unavailable, but other websites work fine.
How to troubleshoot OS X user accounts
This process involves creating a new user account, logging in to it, and testing for the issue.
- Create a new standard or admin user account in Users & Groups preferences.
- Optional: If you have any specific files you wish to test with, copy (don't move) those items to the /Users/Shared folder in the Finder.
- Log out of your current user account by choosing Log Out from the Apple () menu.
- Log in with the new account you created.
- Attempt to reproduce the issue you were seeing in your regular user account.
Note: If you were using any specific settings that the issue depends on (such as using a specific email account, iCloud account) then you should set up that account in System Preferences in the test user. For email and most other settings you should be able to set these preferences in the Mail, Contacts & Calendars pane of System Preferences. If you copied any files to the /Users/Shared folder that you need for testing, you'll want to copy these to the desktop (or other applicable locations) of the test account.
- Important: After you have completed testing, log out of the test account by choosing Log Out from the Apple () menu.
- Log in as your regular account.
- After you have completed all testing with the test user account, you may want to delete it. You can delete an account in the Users & Groups pane of System Preferences.
Note: Prior to deleting a test account, make sure you are completely done with it. If you have files in the Guest User you wish to keep, you should copy them to the /Users/Shared folder .
If the issue happens in only one user account
If you have isolated an issue to a single user account, then you should focus your troubleshooting on that user and specific apps that have symptoms when logged in as that user. Mac OS X: How to troubleshoot a software issue provides some assistance with this. If you are just seeing the issue in one account, you most likely do not need to reinstall any apps.
If you are seeing issues with an application unexpectedly quitting in just one account:
- See this help article for additional assistance in OS X Mavericks.
- See this help article for additional assistance in OS X Mountain Lion.
- see this help article for additional assistance in OS X Lion.
Other, app-specific issues isolated to a single user account can be caused by a preference file (plist) or setting. Check the app's documentation or support website for instructions on troubleshooting specific preference or setting files. For example, iLife preference troubleshooting is documented in iLife: Troubleshooting Basics. If you are looking for help with troubleshooting a specific alert message or issue, you should try searching the Apple Support website for the text of the alert message you're seeing.
If you need more help with troubleshooting an issue isolated to a specific user account, you may wish to contact Apple Support. If you work with AppleCare to troubleshoot the issue, be sure to mention any troubleshooting steps you have already performed and the results, and the text of any alert messages you're seeing. You may want to take a screenshot of any alert messages so you can refer to them later.
If you find that you frequently need to test with another account, you may want to enable and use a Guest User account instead of creating new test users every time.