Mainstage-3.6.4.dmg

You are trying to install on an older OS. Consider upgrading to Catalina via an external boot drive or finding a much older version (MainStage 2.x for Snow Leopard).

: If you are also a gamer or a mobile strategist, you might find the layout tools in the Maps for Clash of Clans app on Google Play or the Apple App Store useful for planning complex setups—though for MainStage, your "base" is your MIDI controller! MainStage-3.6.4.dmg

Before you attempt to mount and install , ensure your setup matches these requirements: You are trying to install on an older OS

(if present) – usually License.txt inside. MainStage-3.6.4.dmg