Macs equipped with the T2 security chip need to have a security setting altered to allow the use of bootable external devices. T2-Equipped MacsĬreating and using the macOS bootable installer requires your Mac to be able to start up from an external drive. There should be an option available to continue the download.

Note: You may see a warning about downloading an older version of the operating system.

Do not allow it to start the install process. If the installer starts up automatically, be sure to quit the installer. You can find the installers available at:ĭownload the installer of your choice. We can show you how to create the bootable installer, but first you’ll need to download the macOS installer from the Mac App Store. The Mac OS installers are still available from the Mac App Store, provided you know the download URL. If you go the clone route, make sure the cloning software you use is both APFS and macOS Catalina compatible Carbon Copy Cloner and SuperDuper are two good possibilities. The other option is to make a clone of the startup drive. Time Machine is one option for a backup just make sure Time Machine has been run shortly before you start the downgrade. Back Up Your Current Dataīecause of the need to erase your startup drive, the downgrade process should start with backing up all of your data. The volumes that currently house your copy of macOS Catalina will have to be erased in order to convert the two special Catalina volumes (one read-only system volume and one read/write data volume) back to a format that is usable by the earlier versions of the Mac OS. With any of the downgrade methods, you’re going to lose all the data currently on your Mac.

Use Time Machine to restore from a date when your Mac was using a previous version of the o perating system.

Reinstall a previous version of the Mac OS using the appropriate Mac OS Installer.

There are a few different ways to perform the downgrade here are two of them. What You Need in O rder to Downgrade from macOS Catalina With those caveats in mind, let’s start the downgrade process. If you’re downgrading because of macOS Catalina installation problems, be sure to check the Catalina Install Issues section near the end of this article for any special steps you may need to take. If you would like to downgrade from macOS Catalina to a previous version of the Mac operating system it can be done, but it isn’t always an easy or painless process.

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