Guide · macOS
Audio plug-ins missing or not loading after a macOS update
You updated macOS, opened your session, and half your plug-ins are gone or greyed out. Here's what the update actually changed, and how to bring them back.
Why an update breaks plug-ins
A macOS update doesn't delete your plug-ins. It changes the rules for loading them. Two things happen:
- Stricter signature checks. Each release can tighten how Gatekeeper validates code signatures. Plug-ins that were signed with older or ad-hoc signatures (common with many audio plug-ins) can suddenly fail validation and get refused.
- Plug-in caches get invalidated. Your DAW keeps a cache of “known good” plug-ins. After an OS update (or a DAW update), that cache is often rebuilt, and any plug-in that now fails validation is dropped from the list.
The result: the plug-in file is still on disk, but macOS won't let it load, so your DAW hides it.
Fix it in the right order
1. Re-sign the plug-ins
This is the step that actually resolves the “damaged / can't be verified” failures. For each affected plug-in, clear stale attributes and apply a fresh ad-hoc signature:
sudo xattr -cr "/Library/Audio/Plug-Ins/VST3/YourPlugin.vst3"
sudo codesign --force --deep --sign - "/Library/Audio/Plug-Ins/VST3/YourPlugin.vst3"Do this for anything that went missing. If a whole folder is affected (which is typical after an update), that's a lot of commands to type by hand.
An update usually breaks many at once
That's exactly what Plugin Medic is for. Drop a single plug-in for free, or unlock batch mode to drop your whole VST3 or Components folder and re-sign every plug-in in one pass, with a per-item result so you can see what got fixed.
2. Rescan in your DAW
Once the plug-ins are signed, force your host to re-validate them:
- Logic Pro: Settings → Plug-in Manager → select the plug-ins → Reset & Rescan.
- Ableton Live: Settings → Plug-Ins → toggle the plug-in sources off and on, or use Rescan.
- Pro Tools: quit and relaunch; it re-scans AAX on launch.
- Most others: a full quit-and-reopen triggers a fresh scan.
3. Clear the Audio Unit cache (AU only, if still stuck)
If Audio Units specifically won't reappear, resetting the AU validation cache forces macOS to re-examine them on next launch:
killall -9 AudioComponentRegistrarThen reopen your DAW. It will re-validate the Components folder from scratch.
Prevent it next time
Before a major macOS upgrade, it's worth knowing your plug-ins may need re-signing afterward. It's routine, not a disaster. Keeping Plugin Medic around means the fix is a folder drop instead of an afternoon in Terminal.