Logic Pro fix

Logic Pro stuck scanning Audio Units? Get it to launch again

Short answer. Logic freezes on scanning Audio Units when one plugin fails or stalls validation. Try Logic's own tools first: clear the alert in Mission Control, or open the Plug-in Manager and turn the plugin off. If Logic will not open at all, you cannot reach the Plug-in Manager, so disable the failing Audio Unit from disk to get Logic booting, then re-enable it. Ainola does that disk step in one reversible click, with nothing deleted.

Last updated 24 June 2026

Why Logic Pro gets stuck

One Audio Unit stalls the launch scan. At startup Logic validates every Audio Unit installed on your Mac. If one is incompatible, unsigned, or slow to validate, the scan stops on it, often showing updating information about Audio Unit plug-ins or finalized 0 of 1, and Logic never finishes opening. It usually starts right after a macOS update or a fresh plugin install.

Try Logic's own tools first

These are the right fix when Logic can still open. Work down the list:

  1. Open Mission Control and click any plugin alert that is waiting behind Logic, so the scan can continue.
  2. If Logic opens, go to Logic Pro, then Settings, then Plug-in Manager, find the failed plugin and turn off its Use checkbox, then quit and reopen.
  3. Use the Audio Unit safe mode to load Logic without the failing plugins so you can see which ones failed.
  4. Update the plugin to a version that validates, then turn it back on.

Clearing the Audio Unit cache in ~/Library/Caches/AudioUnitCache can also force a clean rescan. Ainola does not touch that cache, it works on the plugin files themselves.

When Logic will not open at all

You cannot reach the Plug-in Manager if the app never launches. When Logic hangs on the scan every time, the only way in is to take the plugin out of the folder Logic reads. Apple documents this for Audio Units: hold Command and drag the plugin file out, then start Logic.

  1. Quit Logic.
  2. In Finder choose Go, then Go to Folder, and enter /Library/Audio/Plug-Ins/Components.
  3. Hold Command and drag recently installed or suspect plugins to a temporary folder on your Desktop.
  4. Open Logic. If it launches, add plugins back a few at a time until you find the one that breaks the scan.
  5. Leave that plugin out, or update it from the maker.

Do the disk step in one click (Ainola)

Ainola is the one-click, reversible version of that Command-drag. It lists every Audio Unit, VST and VST3 with a switch, disables them on disk so Logic can launch, and re-enables them exactly when you are done. Disable a batch, then re-enable in groups to find the culprit, with nothing deleted and no DAW needed to do it. It does not make a plugin pass validation, it gets Logic open so you can deal with the plugin.

The Ainola plugin list with a switch on every Audio Unit, VST and VST3
Every plugin with a switch. Turn the suspect Audio Units off so Logic launches, then re-enable, nothing deleted.
  1. Download Ainola and open it on another Mac account or while Logic is closed.
  2. Switch off the Audio Units you suspect, or a batch to be safe.
  3. Apply with one password prompt, then open Logic. It launches past the scan.
  4. Re-enable in groups to find the plugin, and update or leave out the one that breaks it.

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Related questions

Why does Logic Pro get stuck on one plugin? +

At launch Logic validates every Audio Unit on your Mac. If one is incompatible, unsigned, or slow to validate, the scan stalls on it, often showing updating information about Audio Unit plug-ins or finalized 0 of 1, and Logic never opens.

Does Ainola fix Audio Unit validation? +

No. Ainola does not make a plugin pass validation. To do that you update the plugin or use Logic's own Plug-in Manager to disable failed Audio Units. What Ainola does is disable the plugin from disk so Logic can launch when it is too stuck to reach the Plug-in Manager, then you re-enable it.

Will I lose the plugin if I disable it? +

No. Disabling only renames the plugin file so Logic skips it. Re-enabling restores it exactly, and your other hosts see it again.

Which macOS versions are supported? +

macOS 12 Monterey or later, on Apple Silicon and Intel.

Sources

Related fixes: disable a plugin on Mac without uninstalling, Sibelius slow to open, Sibelius stuck scanning plugins.