Soundtrack Pro doesn't like 32 Khz Audio, sometimes

Apple has officially acknowledged a known issue for Soundtrack Pro.

Soundtrack Pro sometimes displays the message "An Unexpected Problem: Uncaught exception." This may happen when you process audio with some third-party Audio Unit plug-ins.

The fix is to resample your audio file.

This may occur when you process audio files with a 32 kHz sample rate with these plug-ins, or when you export projects that use them to a 32 kHz file format. When working with Waves, Universal Audio, or TC Powercore plug-ins, if you see this issue, convert any 32 kHz files in your project to 44.1 kHz