MainStage 4.3 hangs on launch. Stuck on "waiting for Audio Units"

Question

Level 1

20 points

MainStage 4.3 hangs on launch. Stuck on "waiting for Audio Units"

So I can't figure this out. When I launch MainStage, I wait for it to initialize and scan Audio Units, then I go to open recent to open up a concert I am using, and every first time, the concert hangs on the "Waiting for Audio Units" dialog box. I then force quit, re-open MainStage and instead of open recent, I double click on the actual concert file, most times the concert opens up fine without incident, but this should NOT be expected behavior. I've already gone through searching for a potential "bad" plug-in by moving all third party plug-ins' out of my components folder, and trying again. The same thing happens. Any help would be most appreciated.

MacBook Pro 16″

Posted on Jul 3, 2026 4:19 PM

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Answer 1

rjldubois

Level 3

698 points

Jul 3, 2026 4:21 PM in response to keyboardist

Hello keyboardist, and welcome to the Apple Support Community.

If MainStage consistently hangs on “Waiting for Audio Units”, the most common cause is a third-party Audio Unit plug-in that fails validation or becomes unresponsive during startup.

You could try the following:

Start MainStage while temporarily removing or disabling any recently installed Audio Units to determine whether a specific plug-in is causing the issue.
Open Plug-in Manager (if MainStage can be launched) and rescan or disable the affected Audio Unit.
Verify that all third-party plug-ins are fully compatible with macOS Tahoe and MainStage 4.3, as older plug-ins may prevent the scan from completing.
If the issue began after an update, restarting the Mac in Safe Mode can help determine whether the problem is caused by third-party software loading at startup.

Helpful links:

MainStage User Guide - Apple Support

Start up your Mac in safe mode - Apple Support

Could you let us know whether MainStage hangs with all Audio Units disabled, or if the problem started after installing a particular plug-in?

Your feedback may help other members of the Apple Support Community experiencing the same issue.

🙏🏻

Have a good Day.

And one more thing…

Never forget to think different.

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