MainStage won’t load…says issue with midi driver…and Audio MIDI Set up won’t load

Hey there, and welcome to Apple Support Communities jmccord,

We can certainly understand your concern and can help provide some insight.

We recommend checking out these steps for more information on what to do if you are having issues with applications on your Mac.

" If an app on your Mac stops responding, closes unexpectedly, or won’t open

If an app on your Mac does not work as expected, try this.

1. Quit and reopen the app

Quit the app, then open it again. If the app won't quit, force the app to quit. Then check to see if the problem with the app is fixed.

2. Restart your Mac

Restart your Mac. Then check to see if the problem with the app is fixed.

3. Check for updates

To see if updates are available for the app, open the App Store, then click Updates. If updates aren't available for the app, update the software on your Mac. Or if you didn't get the app from the App Store, look for updates to the app on the app developer's website. Then check to see if the problem with the app is fixed.

4. Reinstall the app

Delete the app. When you do this, you might lose data that was stored in the app. Then redownload the app. If you didn't get the app from the App Store, redownload the app on the app developer's website. Then check to see if the problem with the app is fixed.

Get more help

• If you found the app on the App Store, contact the app developer. If the app is made by Apple or came with your Mac, or if the App Store itself is not responding, contact Apple Support. "

For additional information, check out this link: If an app on your Mac stops responding, closes unexpectedly, or won’t open - Apple Support

These steps will help ensure your device is working with ease and can fix common issues like the ones you’re experiencing.

Kindest regards!

Same here. I wish I had backed up before updating the OS.

Previous OS worked great.

Audio programs lagging and no MIDI.