In some situations, Audio Unit plug-ins may not be automatically rescanned and validated by Logic Pro / Mainstage or Garage Band which are relying on the "AUvaltool" (Audio Units Validation Tool).
By following the steps below, you should be able to force a rescan for it to occur on the next opening of your preferred DAW :
- First, make sure to close Logic Pro / Mainstage or Garage Band
- In the Finder, choose Go > Go to Folder from the menu.
- Type ~/Library/Caches in the "Go to the folder" field.
- Press the "Go" button
- Make sure once inside this folder to open the "AudioUnitcache" folder and then to delete the "com.apple.audiounits.cache" and "com.apple.audiounits.sandboxed.cache" files contained inside it:
The next time you start Logic Pro, Mainstage or Garage Band the installed Audio Unit plug-ins will be scanned and available again to insert them on your projects tracks.
The process can be more or less lengthy depending on the amount of Audio Unit plug-ins installed.
- In case any further problems would persists, make sure to also refer to the following articles below:
Apple Support - If you can’t find a recently installed plug-in for Logic Pro or MainStage
Apple Support - Remove or disable Audio Units plug-ins in Logic Pro or MainStage
- You can also refer to the following article to find other suggestions and find out how to force a plug-in rescan with other DAWs: