Resolution

Confirm requirements and versions

1. Check system requirements
   Make sure that you haven't overlooked any hardware aspect that's required to use Logic Pro.
2. Update to the latest software versions
   Choose Apple () > Software Update and make sure that you have the most recent updates for your versions of Logic Pro, QuickTime, and other important system files. Installing the latest updates ensures that your software has the latest improvements and enhancements.
3. Check compatibility and driver versions for third-party devices
   If you're using a third-party sound card, MIDI interface, storage system, control surface, or plug-ins, check the support area on the manufacturer's website to be sure that you're using the latest version of the relevant driver or other software for your product. For information on troubleshooting possible issues with Audio Unit plug-ins, see Remove Audio Unit plug-ins to troubleshoot issues.
4. Check for Pro Application Support updates
   Make sure you are using the latest version of Pro Application Support. For more information see Pro applications on PowerPC computers may quit unexpectedly on launch or quit, or display non-customary menus and dialogs.

Test with no audio driver

You can isolate issues with audio devices by launching Logic with no audio driver. Press and hold down the Control key immediately after Logic starts to launch. A dialog asking whether you wish to launch audio drivers will appear. Click "No" and see if Logic launches normally.

Test using the computer's built-in audio hardware

If you use external audio hardware, try setting Logic to use the built-in audio hardware on your computer. Choose Audio > Audio Hardware and Drivers from the main Logic menu. Click the Core Audio tab and choose Built-in Audio from the Driver pop-up menu. If you are using DAE, disable it first. If the issue is resolved using built-in audio, refer to the manufacturer of your audio interface.

Launch Logic with a new default song

Sometimes song files can become damaged, causing unexpected behavior in Logic. If you use an Autoload or other template, damage to the template can cause unexpected results with any song subsequently created from it. To create a completely fresh song hold down the Option key and choose File > New. Test to see if the issue is resolved in the new song. Sometimes, issues with the data in a song can be repaired. Open an affected song and choose Options > Song Information from the main menu. Click the "Reorganize Memory" button.

Delete the User Preferences

You can resolve many issues by restoring Logic Pro back to its original settings. This will not impact your song files. To reset your Logic Pro user preference settings to their original state, do the following:

1. In the Finder, go to ~/Library/Preferences. Note: The tilde (~) represents your Home folder.
2. Remove the "com.apple.logicpro.plist" file from the Preferences folder.
3. Drag the "Logic" folder from the Preferences folder to your Desktop. Note that if you have programmed any custom key commands, this will reset them to the defaults. You can import your key commands from the copy on your Desktop by following the instructions on page 46 of the Logic Pro 7 Reference Manual. If you use the Project Manager you will also need to rescan your system.

Remove receipts and reinstall Logic Pro

Another approach you might consider is reinstalling Logic Pro. To do this effectively, you need to remove the application and its receipts, then install Logic Pro and use Software Update to install additional updates. You don't have to remove everything that was installed with Logic Pro. Follow the steps below to completely reinstall a fresh copy of Logic Pro. Note: Make sure that you have your installation discs handy before starting this.

1. Open the Applications folder.
2. Go to /Library/Receipts.
3. In the Receipts folder, select the "Logic Pro.pkg" file.
4. Choose View > as List to view the contents in a list.
5. Click the Date Modified column header so you can easily see all of the receipts that were installed at the same time as Logic Pro.
6. Drag the Logic Pro.pkg receipt to the Trash, as well as any other items that have the same modification date within 3 minutes of the Logic Pro.pkg's modification date.
7. Click the Name column header to sort the list alphabetically.
8. Drag any other receipts whose names begin with "Logic Pro" to the Trash.
9. Insert your Logic Pro installation disc and install Logic Pro.
10. When finished, use Software Update (under the Apple menu) to update your software to the latest version.

For further information on settings or installation, please refer to the Logic Pro documentation available on your installation discs.