Last Week on My Mac: Better beta-testing

Congratulations: it’s the fourth of July, and Americans around the world are celebrating their independence. That also means it’s time for Apple to open its beta-test programme to all Mac (and iOS etc.) users, as it did last week.

If you’re tempted, I’ve already sounded a cautionary note as to how you can make installing a beta safer. As it happens, this year’s major new release of macOS looks to consolidate rather than make major internal changes, as has happened in recent years. The general consensus is that the first public beta isn’t likely to wipe or destroy your Mac, and in many respects should be an improvement on Big Sur, even at this early stage in testing.

Kernel panics

If you do decide to install the Monterey beta, or have already done so, I have a big favour to ask on behalf of tens of millions of users, and quite a few of Apple’s engineers. By all means take a good look at Shortcuts and Safari, and give Apple plenty of feedback on what you think of them and, in the case of Safari, comment on its changed interface. But please pay careful attention to the basics, exercising your Mac with peripherals such as external displays and hubs. Where you discover problems, please work with Apple to ensure that it knows what they are. If you can, test out features such as Time Machine (being careful not to put your existing backups at risk), which seldom get much attention from other beta-testers.

While it’s important that Apple gets its apps right, we’ve usually got alternatives we can use instead if necessary, but if macOS isn’t stable, or isn’t compatible with a wide range of peripherals, there’s no other option.

In particular, send Feedback reports on any kernel panic which your Mac encounters when running a beta. The normal system report, sent after your Mac has restarted, is helpful, but further details are much better still. Even betas should never suffer kernel panics; if yours does, please help Apple’s engineers fix that problem before Monterey is released.

I’ve recently been contacted by several users whose Macs have been suffering repeated kernel panics, and next week will be writing a guide as to what to do, both in terms of how to address them yourself, and how best to ensure the underlying problems get fixed. Panics, particularly those associated with third-party hardware and software, are one of the most compelling reasons for Apple to open testing to every Mac user. There’s no way that Apple’s engineers can test out the same combinations of hardware and software that we can, so your Feedback here is particularly valuable.

Missing boot disks

If you’re testing the beta on an M1 Mac, then there’s a specific cause of panics which you should watch for, as these occur in Big Sur and, from what I hear, may also affect Monterey betas: the missing external boot disk.

I’ve recently described my own experience with these in Big Sur, where they appear quite reproducible. They rely on you having a bootable external disk, in this case containing the Monterey beta. Start up from that external disk and do a little browsing, or whatever. Then, without changing the startup disk, shut your M1 Mac down. Once it has shut down, disconnect the external disk, then try starting it up again.

As I have described, this can cause a kernel panic during startup, when the startup disk is nowhere to be found. What should happen is that you are either booted straight into recoveryOS to select a new startup disk, or your Mac should default to booting from its internal SSD. Neither of those appear to occur (reliably, at least), causing the panic, which then loops when your Mac tries to start up again.

Given that many testing Monterey betas on M1 Macs will be doing so with the test version of macOS on an external disk, this is also something to watch for during testing. If you want to restart your Mac in Big Sur and disconnect the Monterey disk, use the Startup Disk pane to change the boot disk, restart from your internal SSD, and then unmount the external disk containing the Monterey beta.


One other not infrequent problem with testing betas on an external disk is updating them. The best way to do this is using the Software Update pane in Monterey, but sometimes that refuses no matter what you try, and Big Sur won’t co-operate either. The best way ahead then is to download the full installer for the beta – Mr Macintosh now lists these here – and run that when booted in Big Sur, to install the beta on your external disk. This normally preserves your existing Data volume too, sparing you having to migrate from a backup.

Escape routes

Finally, if you do decide to test Monterey, ensure that your escape is fully planned and tested.

For Intel Macs without T1 or T2 processors, a bootable external disk containing your fallback macOS, such as 11.4, is a valuable asset, and should help you revive your Mac. The one significant drawback is that there’s no way to revert to an older version of the EFI firmware or Recovery system, so if you’ve been experiencing problems with either, then that Mac may be unstable until you install the next EFI firmware in a macOS installer.

T1 and T2 Macs may be able to have their firmware downgraded to the current Big Sur release, if you have a second Mac and Apple Configurator 2. Again, Mr Macintosh lists available and signed firmware for them.

M1 Macs are different again: although it’s a bit of a fiddle, you can restore their firmware complete, including recoveryOS, when they’re connected to another Mac. This requires putting the target Mac in DFU mode and restoring the Mac from there.

If you’re going to run a beta on an M1 Mac, you should have a prepared plan for doing this before installing the beta. Even if you don’t have a second Mac capable of doing the job, you should be able to get this done by an Apple store or service provider. If you only have one Mac and live sixty or more miles from the nearest Apple store, you really shouldn’t be choosing to install the beta.

For those who do beta-test Monterey, I wish us success, and hope you enjoy testing, and helping Apple make Monterey even better for all of us.