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Tutorial: What to do when a Mac OS X application will not launch

Tutorial: What to do when a Mac OS X application will not launch

It?s a frustrating scenario: You click on a regularly used application only to find that it will not launch ? either bouncing indefinitely in the Mac OS X Dock or simply providing no feedback whatsoever. There are a number of potential solutions for this problem, ranging from simple and relatively quick to more tedious.

Update prebinding Many cases of application launch-failure can be resolved easily by simply updating prebinding, via the following steps:

  1. Log in as an administrator
  2. Open the Terminal (located in Applications/Utilities)
  3. Type: sudo update_prebinding -root / -force and press Return.
  4. When prompted for a password, enter your admin password, and press Return again. The process may take a few minutes, and you may see various messages flash by. The process is complete when the Terminal returns to a normal prompt.
  5. Type exit and press Return.
  6. Check for the capability to launch the problematic application.

Kill process in activity monitor Killing an application-related process via Activity Monitor (click the item then press the 'Quit Process' button) can allow proper application launch. This is especially applicable in situations where a restart cures problems with application launching, as the offending process(es) will, of course, be killed by the restart process.

Launch Activity Monitor (located in Applications/Utilities), then find the process associated with the problematic application, then quit it and attempt re-launching the applications.

Delete appropriate .plist files A non-launching application can be the result of a corrupt or otherwise defunct associated .plist file (for more information on exactly what a .plist file is, see this series of articles)

Most of the preferences files that we will be talking about are stored in a folder named Preferences, and located in the Library folder of your home directory, e.g.:

  • ~/Library/Preferences/

Go to the ~/Library/Preferences folder, and search for any .plist files that may be associated with the application you are having trouble with. Drag the .plist file(s) [many applications have more than one associated .plist file, so be careful to scour for all of them] to the Desktop, then re-attempt launching the application.

You can also use an application like Preferential Treatment to check for corrupt .plist files.

Re-install the application Try re-installing your application from its original media or download source.

If an Apple application or component is not launching properly, you might need to restore it from the Apple installation discs per the instructions in our tutorial "Re-installing Apple applications from a Mac OS X disc/update package using Pacifist."

Clearing caches Try using a utility like Tiger Cache Cleaner, OnyX, or Cocktail to perform series of system cache deletion routines. Go from light, to medium to deep (the ordinal levels are defined differently in each application), checking to see if your afflicted application launches properly after each.

Also, check the following folder for application-specific cache files that can be deleted, or at least temporarily removed:

/Library/Application Support (look inside the folders here for files that end with .cache, and delete them)

Make sure permissions are correct A range of permissions issues can effect Mac OS X applications, causing them not to launch.

In these cases, the first thing to try is a disk permissions repair routine using Apple's Disk Utility (located in Applications/Utilities).

Failing that, startup from your Mac OS X installation disc (insert it, then restart while holding down the "C" key). After the startup process is complete, go to the "Utilities" menu and select Disk Utility. Click on the First Aid tab, then click on the Repair Disk button.

In some odd cases (usually after a backup or when transferring backed up data back to a startup device), permissions on the "MacOS" directory (the directory that normally stores the executable binary in a Mac OS X application) can become incorrect.

In order to fix this problem, use the following steps:

  1. Click on the afflicted application to select it in the Finder
  2. Either click the application while holding the control key, or use the "Action" menu (the icon looks like a gear) to access the option "Show Package Contents"
  3. Open the "Contents" folder therein, and then find the "MacOS" folder
  4. Modify the permissions on this folder to give it "execute" permissions for all users. Do this by opening the Terminal (located in Applications/Utilities) and typing the following command (don't press return afterward):
  5. sudo chmod 755
  6. After typing this, drag the "MacOS" folder to the Terminal window -- its path should appear. Press return, and you will be prompted for your administrator password, which you should enter.
The "MacOS" directory should now have read, write and execute priveleges for the owner, and read and execute privileges for the group and others.

Check CoreAudio As noted in Knowledge Base article #301658, some Apple applications might not open fully or at all if the Digidesign Core Audio driver has been installed as part of a Pro Tools version 6.9 installation.

Apple says to follow these steps if you are affected by this issue:

  • Updating your Digidesign Core Audio driver may resolve the issue. You can find the latest versions for Mac OS X 10.3 (Panther) and Mac OS X 10.4 (Tiger) at If that doesn't help, continue to step 2.
  • Open Audio MIDI Setup (/Applications/Utilities).
  • Click the Audio Devices tab.
  • From the Default Output pop-up menu, choose Built-in Audio.

Check for errant plug-ins Some application launch failures can be caused by problematic plug-ins or other add-ons. Safari and other Web browsers are notorious for suffering from this issue, as are some other extensible applications like iMovie.

Check the following locations for any recently added files, or any files implicated in error messages generated when you attempt to launch the problematic application:

  • /Library/Internet Plug-ins
  • ~/Library/InputManagers

Re-apply the Mac OS X combo updater Try re-applying the latest Mac OS X combo updater from Apple's software downloads page. Doing so can resolve issues with system components or delete specific files that can resolve application launching issues.

Create a new user account Try creating a new user account, and check if the application launches under it. If so, a user-specific corruption issue is likely at play -- see the above sections regarding .plist files and caches. See our tutorial "Common workaround -- create a new user account" for more information.

Archive and Install As a last resort, try performing an Archive and Install process, which will retain some user settings but otherwise leave you with a fresh Mac OS X installation.

Also, check with the application's developer for compatibility notes regarding the version of Mac OS X you are running, and revert to an earlier iteration if necessary.

Like what you've found in this tutorial? Get more troubleshooting guidance (updated daily) by subscribing to MacFixIt Pro.

  • series of articles
  • Preferential Treatment
  • "Re-installing Apple applications from a Mac OS X disc/update package using Pacifist."
  • #301658
  • software downloads page
  • "Common workaround -- create a new user account"
  • Archive and Install proces...
  • revert
  • subscribing to MacFixIt Pr...
  • More from Tutorials