To resolve this issue, update to GarageBand 6.0.2 or later.
If GarageBand was included with your computer or if you installed GarageBand from a DVD:
- Download and install GarageBand 6.0.2 or later by choosing Software Update from the Apple () menu.
If you purchased GarageBand from the Mac App Store:
- Download and install GarageBand 6.0.2 or later from the Updates tab of the Mac App Store.
For earlier versions of GarageBand, try the following solutions:
- If you have audio hardware not manufactured by Apple, try switching the device GarageBand uses for input and output between the built-in audio and back.
- Quit and reopen GarageBand.