Trouble updating to macOS Tahoe
I keep getting the error “A snapshot is currently set to boot that is not the currently booted snapshot. Reboot to boot to the new snapshot to allow installation to this volume”
MacBook Air, macOS 15.0
It appears you have a pending update for your currently installed OS. Proceed with finishing that software update.....there is a chance it may also be due to a third party app. Rebooting the computer normally may be all that is required if the update has already finished staging within that snapshot. FYI, macOS stages macOS update patches using APFS snapshots in order to help make the updating process quicker when a reboot is required. I think some third party apps may also trigger this as well since I have seen an "update" snapshot named for Microsoft.
If you thought you had all your macOS update patches installed, think again. Apple release another update patch for Sequoia this morning (15.7)....even Sonoma may have received one (I only heard about 15.7 so far).
Once you finish updating your current OS & rebooting, then you should be able to upgrade to Tahoe, but be warned that Apple's servers are being overwhelmed today (and likely most of this week) since a lot of people want to rush to it (I have no idea why when things may still be broken, I always wait until the first patch). Plus iOS 26 was released today as well.
Make sure to have a good backup of your system before you perform the Tahoe upgrade just in case you need to downgrade back to Sequoia for some reason.
