Settings to Check After a macOS Update

A macOS update is not just new features. Major upgrades reset some preferences, re-enable a few services, add new settings that default to on, and occasionally retire a hidden key you were relying on. This is the fifteen-minute pass worth doing afterwards.

Privacy, first

Major upgrades introduce new categories and occasionally re-prompt for old ones. Check all of these in System Settings → Privacy & Security:

1. Analytics & Improvements — new sharing options appear here, defaulted on.
2. Apple Advertising — check personalised ads is still off.
3. Location Services — look at System Services → Details at the bottom, where new entries land.
4. Screen Recording, Camera, Microphone, Full Disk Access — apps you have deleted may still be listed, and apps that updated may have re-requested.

Sharing services

Open System Settings → General → Sharing and confirm nothing is on that you did not turn on. Media Sharing, Content Caching, Printer Sharing and Remote Management are the ones to watch. Each of these also prevents the Mac sleeping, which is why "my Mac stopped sleeping after the update" is such a common report.

Hidden settings that may have reset

Major upgrades sometimes reset preference domains. Rather than guessing, read the values back:

# check the ones you rely on; an error means it is no longer set
defaults read com.apple.screencapture disable-shadow
defaults read com.apple.dock autohide-delay
defaults read NSGlobalDomain KeyRepeat
defaults read com.apple.finder AppleShowAllFiles

Anything that errors needs re-applying. This is the argument for keeping a written list of the settings you change, or a tool that keeps the list for you: without one, you rediscover them by being annoyed at each in turn over the following month.

Login items and background helpers

Updates reinstall components, and apps that updated alongside macOS often re-add themselves. Open System Settings → General → Login Items and check both lists, especially Allow in the Background. A slow login after an update is nearly always this.

Notifications and Focus

New system apps arrive with notifications enabled, and Focus filters sometimes need re-approving. Skim System Settings → Notifications for anything new, and open your Focus modes to check the filters survived. Worth confirming: Allow notifications when mirroring or sharing the display is still off, which matters the first time you share a screen after the update.

Give the disk and the battery a week

Two figures look alarming immediately after an upgrade and correct themselves. Free space drops, because the installer keeps files for a rollback and Time Machine takes a fresh set of local snapshots; that recovers over the following days. Battery life looks worse, because indexing and re-analysis run in the background at exactly the moment you are watching.

Judge both after a week of normal use. If free space has not recovered or the battery is still noticeably worse, then it is worth investigating — and at that point Activity Monitor → Energy over a full day is the tool that will name the cause, rather than any guesswork about the update itself.

The things that break, and what to do

• Menu bar spacing changes — the -currentHost spacing keys reset on some upgrades and need re-applying.
• Default apps revert — check that PDFs, images and web links still open where you want, in each file's Get Info → Open with → Change All.
• Printers stop working — remove and re-add the printer rather than troubleshooting the driver.
• Third-party utilities need updating — anything using accessibility, screen recording or system extensions may need permission granted again.

Finally, give the Mac a day before judging it. Spotlight reindexes after an upgrade and Photos re-analyses its library, both of which consume significant CPU and make everything feel slower. That settles on its own, and it is the reason so many "the update ruined my Mac" reports quietly disappear by the weekend.