rescan audio unit in garageband

You can try resetting the AU cache manually, per the second instructions here. Garageband should rescan the next time it opens.

https://support.sonnox.com/support/solutions/articles/22000156666-re-scanning-au-plug-ins-in-logic-and-garageband

Hi doublenick,

Welcome to the Apple Support Communities!

We understand that you'd like to use an Audio Unit plug-in in GarageBand, correct? Here's a handy resource which will show you how to add it: Use Audio Units plug-ins with GarageBand on Mac

We hope this helps.

Cheers!

No, nicola is asking how to rescan, because a particular AU isn't showing up. I have the same problem.