This can sometimes occur when updating FreeMIDI to a newer version. Here are the steps to resolve this problem.

1. Quit all applications
2. Trash the following items:

- FreeMIDI Applications (on Mac HD)
- FreeMIDI Folder (inside System Folder)
- FreeMIDI PowerPlug (inside System Folder >>> Extensions)
- FreeMIDI System Extension (inside System Folder >>> Extensions)
- FreeMIDI Softsynth Extension (inside System Folder >>> Extensions)
- FreeMIDI Preferences (inside System Folder >>> Preferences)
- FreeMIDI Setup Prefs (inside System Folder >>> Preferences)

3. Restart your Mac & empty the Trash
4. Use your MOTU USB installer CD, or Software (Digital Performer, etc) to perform a custom install of FreeMIDI.
5. Restart your Mac once more, launch FreeMIDI and create a new configuration.