GarageBand for Mac (v10.0) is a 64-bit application and works with 64-bit Audio Units plug-ins. 32-bit Audio Units plug-ins are not compatible. Check with the plug-in manufacturer for an updated version of the plug-in that is compatible with GarageBand for Mac (v10.0).

For some Audio Units plug-ins that require authorization, you might need to authorize them again before you can use them.