I see you're looking for information on MainStage 3.4.2 and its compatibility with macOS, specifically regarding a potential crack for Mac OSX in 2021.
The Risks Associated with Cracked Software
System Instability: MainStage is designed for live performance where reliability is everything. Cracked versions are often prone to crashing, MIDI lag, or plugin failures because the software’s integrity has been compromised [1, 5].
In software contexts, a "crack" usually refers to a hacked version of a software application. This could mean someone has bypassed the software's protection mechanisms to use it without purchasing a license or subscription. Using cracked software can lead to several risks, including but not limited to:
It looks like you’re looking for a cracked version of Apple MainStage 3.4.2. While the idea of getting pro software for free is tempting, downloading "cracks" for macOS usually ends up causing more headaches than they solve.
Conclusion