macOS ISSUES

Shine a spotlight on sagacious solutions to your most maddening Mac maladies

Sagacious solutions to Mac maladies

Hard route back to Sierra

I’m having problems with High Q Sierra – it’s taking ages to verify my videos, which use to play almost instantly. How can I get back to Sierra? The first thing you need is a copy of A a recent Sierra installer. If you don’t have one to hand, you may already have noticed this version of the system is no longer openly listed on the Mac App Store, and doesn’t appear in the Purchased tab. Look down the page at bit.ly/dlsierra to find a link that will open Sierra’s otherwise hidden product page to download the installer.

If you already have a copy tucked by, you’ll need an 8GB USB memory stick or external drive formatted and set up as a bootable installer. This is easily done using DiskMaker X (diskmakerx.com), or you can follow Apple’s instructions in Terminal at bit.ly/bootinstall.

The other essential ingredient is a very recent backup, such as that made by Time Machine, from which to restore your Home folder and third-party apps.

Start up from the bootable installer drive through the Startup Disk pane, or by selecting it in the Startup Manager (hold the key during startup). If your normal startup disk was converted to APFS, you’ll next have to reformat it using Disk Utility from the bootable installer; if it’s still in HFS+ format, that is optional but probably a wise choice.

Then install Sierra, bring it fully up to date to version 10.12.6, and migrate files and apps from your backup using Migration Assistant.

Before you can revert back to Sierra, you’ll need a copy of its installer app, which does not appear in your Purchased list.