There's a few ways to catch it, but in your log it was any of the following:
Log.txt for X-Plane 12.0.8-rc-3 (build 120810 Apple Silicon, Metal f343e8d53217a69b4de55c1c775e143ef86b5c6c)
dlerror:dlopen(/Volumes/AC Media/X-Plane 12/Resources/plugins/Gizmo64.plugin/mac_x64/Gizmo64.plugin.xpl, 0x0006): tried: '/Volumes/AC Media/X-Plane 12/Resources/plugins/Gizmo64.plugin/mac_x64/Gizmo64.plugin.xpl' (mach-o file, but is an incompatible architecture (have 'x86_64', need 'arm64'))