GarageBand '08: Longer projects may not export correctly
Sometimes, when you export a song or podcast, there may be no file, a very small file, or an empty file when the export completes. With GarageBand 4.1.2, you may see a dialog warning that the export can not be performed.
There is a known issue with longer projects. The issue varies, depending on the type of audio file you export, the Auto Normalize setting, and which version of GarageBand 4 you are using.
To change the Auto Normalize setting:
Choose GarageBand > Preferences.
In the Advanced panel, set the Auto Normalize option.
GarageBand 4.1.2 has the following export length limits. If you try to create an export that exceeds the length limit, a warning dialog will come up:
16-bit AIFF, Auto Normalize On
24-bit AIFF, Auto Normalize On
16-bit AIFF, Auto Normalize Off
24-bit, Auto Normalize Off
*16 or 24-bit AAC or MP3 files with Auto Normalize on that exceed 1h 41min will not have updated media previews. 16-bit AAC or MP3 files with Auto Normalize off that exceed 3h 20min will not have updated media previews. 24-bit AAC or MP3 files with Auto Normalize off that exceed 2h 13min will not contain media previews.
GarageBand 4.0 - 4.1.1 has the following length limits. If you attempt an export that exceeds these lengths, there will be no warning, and the resulting file will not be usable:
16-bit (any type), Auto Normalize On
24-bit (any type), Auto Normalize On
16-bit (any type), Auto Normalize Off
24-bit (any type), Auto Normalize Off
This document will be updated as more information becomes available.