If for some reason you need to reset the Audio Units
cache, try this procedure:
In Finder, go to Go then Go to Folder... in the menu bar at the top
Copy-paste this path ~/Library/Caches then click Go
Remove the folder named 'AudioUnitCache'
Remove the file named 'com.apple.audiounits.cache'
The image below
has been reduced in size. Click on it to see the full version.