If for some reason you need to reset the Audio Units
cache, try this procedure:
In the Finder, press Option and choose Go > Library.
In the Finder window, go to Library/Caches/AudioUnitCache.
Move the files from AudioUnitCache folder to the Desktop
Restart your Mac, then open your DAW. All installed Audio Units plug-ins will be rescanned
The image below
has been reduced in size. Click on it to see the full version.