Logic Pro crash and Alchemy tuning issue

Are you running Logic under Rosetta? If not, try that.
Try turning off OpenGL —

  • Press CMD+Space to open the Spotlight Search and type “ ScalerSettings
  • Go to the Help page and click “Turn OFF OpenGL”:

Could you take a screen shot of this before and after. Are you using DAW sync?
If you are hearing hissing it sounds like you might not be registered. Click on the Logo in the upper left and the click on registration to see if it shows it is registered.
You say it’s not usable anymore. Was it usable when you first installed it? What changed in your set up?

Do you have MIDI feeding back into Scaler from somewhere other then your keyboard?