Hello,
I mistakenly updated Sequoia to Tahoe.
I urgently need to revert to the previous version, 15.7.7, of Sequoia.
I have a Macbook Pro M1 16Gb, and I have a full backup that I made using CCC.
I tried using a step-by-step CCC recovery guide, but I was unsuccessful.
Could someone help me?
Thank you.
[Re-Titled by Moderator]
Original Title: Downgrade Tahoe to Sequoia
MacBook Pro 16″, macOS 26.5
Downgrade is not in Apple's vocabulary.
Downgrading to an earlier macOS version is an unsupported process that is not to be taken lightly. It's easier and wiser to work through any problems you are experiencing in the newer version than trying to downgrade.
Before proceeding, make sure you have backups of your user data.
1) (strongly recommended) Download the older macOS version and create a bootable USB installer for it on a USB flash drive. This is insurance in case reinstalling macOS in recovery mode (step 4) goes sideways. Check that the USB installer is properly bootable before proceeding.
2) Startup in Recovery and Erase your Mac drive.
Use Disk Utility to erase a Mac with Apple Silicon - Apple Support
3) Reinstall macOS from Recovery startup. Recovery may not offer up Sequoia as an installable option. If it does not, then the fallback is to use the bootable installer you created in 1).
How to reinstall macOS - Apple Support
❝On a Mac with Apple Silicon:
Recovery installs the current version of the most recently installed macOS.
If you installed a macOS upgrade and then used Disk Utility to erase the disk, you might get the macOS that you were using before upgrading.❞
a) (optional fallback) Reinstall the older macOS using the bootable USB installer you created.
4) Restore your data and files from your backup.
Downgrade is not in Apple's vocabulary.
Downgrading to an earlier macOS version is an unsupported process that is not to be taken lightly. It's easier and wiser to work through any problems you are experiencing in the newer version than trying to downgrade.
Before proceeding, make sure you have backups of your user data.
1) (strongly recommended) Download the older macOS version and create a bootable USB installer for it on a USB flash drive. This is insurance in case reinstalling macOS in recovery mode (step 4) goes sideways. Check that the USB installer is properly bootable before proceeding.
2) Startup in Recovery and Erase your Mac drive.
Use Disk Utility to erase a Mac with Apple Silicon - Apple Support
3) Reinstall macOS from Recovery startup. Recovery may not offer up Sequoia as an installable option. If it does not, then the fallback is to use the bootable installer you created in 1).
How to reinstall macOS - Apple Support
❝On a Mac with Apple Silicon:
Recovery installs the current version of the most recently installed macOS.
If you installed a macOS upgrade and then used Disk Utility to erase the disk, you might get the macOS that you were using before upgrading.❞
a) (optional fallback) Reinstall the older macOS using the bootable USB installer you created.
4) Restore your data and files from your backup.
User Risk Assessment: macOS Downgrade Procedure
Before initiating any downgrade from macOS 26 (Tahoe) to an earlier version such as macOS Sequoia, assess the user’s tolerance for potential risks. The following checklist must be completed before proceeding.
Primary System Dependency
Determine whether the affected Mac is the user’s primary or only computer.
If the user cannot function without this system for several days in the event of a failed downgrade, the risk level is high.
The downgrade should be postponed or avoided until proper contingency measures are established.
Availability of a Secondary macOS System
Confirm that the user has access to another Apple computer currently running macOS 15 or macOS 26 (Tahoe).
This secondary system must be capable of performing a Revive or Restore operation on the target Mac’s firmware if required.
Lack of a secondary Mac significantly reduces the ability to recover from firmware corruption or boot failures.
Firmware Compatibility and Secure Enclave Risks
Be aware that upgrading to macOS 26 (Tahoe) likely includes a firmware update affecting the logic board and Secure Enclave Processor (SEP).
Downgrading to an earlier version (e.g., Sequoia) may or may not introduce firmware mismatch issues, leading to instability or loss of functionality.
Backup Integrity and Recovery Preparedness
Verify that the user has at least three complete backups created before the macOS 26 (Tahoe) upgrade.
Implement the 3-2-1 Backup Strategy:
3 total copies of essential data
2 different backup methods or storage media
1 copy stored offsite (for protection against natural or human-caused disasters)
Each backup should reside on a dedicated, single-purpose external drive.
For enhanced backup and cloning capabilities beyond Time Machine, refer to:
Recommendation Summary
If the user answers NO to any of the above questions:
Downgrading the Mac is not recommended.
Proceeding without proper contingency plans, verified backups, and recovery tools may result in:
Data loss
Firmware corruption
Secure Enclave failure
Complete system inoperability
You'll need to boot into recovery and erase the MacBook entirely, then use a bootable USB stick with Sequoia to install it.
Once Sequoia is up and running you should be able to use the backup to restore your files and data.
click the following link for a step by step video on Youtube:
How to downgrade from macOS Tahoe to macOS Sequoia 15.7.7 on MacBook Pro M1?
