If your third-party VST/AU plugins do not appear, ensure you are running MainStage in the correct architecture mode. On Apple Silicon Macs, if an older plugin is not native, you may need to close MainStage, find it in the Applications folder, press Cmd + I (Get Info), and check . Audio Glitches and Pops
Improved connectivity with complex USB-MIDI setups. MainStage-3.6.4.dmg
Built on a 64-bit architecture, MainStage optimizes CPU and RAM usage to minimize audio latency and prevent dropouts during complex transitions or heavy multi-instrument layering. Architecture: Concerts, Sets, and Patches If your third-party VST/AU plugins do not appear,