Garageband 10 Audio Unit gone
I received a response from Antares with the answer


  Once you are in the "Library" folder go to: 
  
  Caches/AudioUnitCache/
  
  Delete the “com.apple.audiounits.sandboxed.cache" file.
  
  Go back to the Library folder, then open the Preferences folder
  
  Once you are in the Library/Preferences folder, delete the file
  "com.apple.audio.InfoHelper.plist"
  
  Empty your trash and restart your computer.
  
  You should now find Auto-Tune 8.1 in GarageBand.


This solved it for me.