"Exclusive class" is an instrument-level parameter most often used on hi-hats so that the closed hi-hat will mute the open hi-hat. However, if exclusive class is set for a sample (value of 1 or higher), Polyphone crashes when that sample is played.
Steps to reproduce:
1. Open the attached SoundFont in Polyphone 2.3 and select the preset.
2. Play any note.
Result: Crash
This happens using the Linux version (compiled from source) and Windows 7 (x64 installer). I haven't tested any other configurations.