Rescanning Sonnox AU Plugins in Logic Pro & GarageBand

Modified on Wed, 30 Jul at 4:12 PM

If your Sonnox plug‑ins are not appearing in Logic Pro or GarageBand, you may need to rescan them so they pass Apple’s AU validation process.

This guide covers the recommended in‑DAW rescan method for modern macOS systems, as well as the manual Audio Unit cache reset for older Logic versions.

Prerequisites

Latest Sonnox plug‑in installers (download here).
Latest iLok License Manager installed and licences activated.
Logic Pro or GarageBand fully closed before any manual file changes.

Step‑by‑Step Solution

1. Rescan from Logic Pro or GarageBand (Recommended)

Open Logic Pro (or GarageBand).
Go to: Logic Pro → Settings → Plug‑In Manager
(Older versions: Preferences → Plug‑In Manager).
In the Manufacturer column, select Sonnox.
Look for unavailable plug‑ins — these will have the Use checkbox unticked.
Select the unavailable plug‑ins, then click Reset & Rescan Selection (bottom right).
Logic/GarageBand will run the AU Validation scan.
- If successful, the plug‑ins will now be available.
- If they fail validation, see [Why Doesn’t My Plug‑in Show Up in My DAW?].

Tip: For GarageBand, the Plug‑In Manager is accessed via GarageBand → Settings → Audio/MIDI → Plug‑In Manager.

2. Perform a Full Audio Unit Reset (If Needed)

If individual rescans don’t work:

In Plug‑In Manager, click Full Audio Unit Reset (bottom left).
Quit and restart Logic Pro or GarageBand.
The DAW will re‑validate all installed AU plug‑ins.

3. Manually Reset the AU Cache (Older macOS / Logic Versions)

For older Logic Pro versions (pre‑10.2) or persistent scan issues:

In Finder, choose Go → Go to Folder… and enter: ~/Library/Caches/
Delete:
- com.apple.audiounits.cache
- AudioUnitCache/com.apple.audiounits.cache
- AudioUnitCache/com.apple.audiounits.sandboxed.cache
Log out of your macOS user account, then log back in.
Re‑open Logic Pro — it will rebuild the cache and re‑validate AU plug‑ins.

Troubleshooting / Alternative Fixes

Still failing validation – Ensure your Sonnox plug‑ins are 64‑bit AU format (required since Logic Pro X) and fully up to date.
Licence issues – Check that your iLok activation is valid and on the correct machine/account.
Repeated validation failures – Some security/privacy settings in macOS may block new plug‑ins; allow them in System Settings → Privacy & Security.

FAQ / Common Questions

Q: Do I need to rescan both Logic Pro and GarageBand?
A: No, they share the same AU validation system, so rescanning in one applies to both.

Q: Will resetting my AU cache delete presets or settings?
A: No, it only clears the scan cache. Your plug‑in settings remain unchanged.

Q: Why do my plug‑ins pass validation but still don’t appear?
A: Check that their category is enabled in Logic’s plug‑in manager, and confirm they are assigned to an instrument or effect slot.