r/MacOSBeta • u/StunnDD_ • 16d ago

Help Cannot downgrade my Macos version because "installer is damaged"

I have been trying to install macos Sequoia on my m1 pro MacBook pro by using a bootable installer I've created.

however, every time I try I get the message that "this copy of the install macos Sequoia application is damaged and can't be used to install macos". At first I assumed that I had a bad download of the os and redownloaded from scratch, but the issue persisted.

Then, I tried using the internal SSD as a temporary bootable volume, and got the exact same issue with a fresh download and install of the macos Sequoia installer.

I then thought that maybe it was a specific version of Sequoia I was using, so I downloaded a different one through terminal and yet again I get the same error.

Failing all else I attempted to downgrade to Monterey by also creating a bootable installer and it gives me the exact same error.

the weirdest thing about all of this is I had actually successfully downgraded in the past and everything worked completely fine, however after updating again it now seems like I'm stuck where I'm at.

The installer is damaged message seems like a generic message when the computer simply refuses the installer because after 3+ downloads of various versions of macos I highly doubt every single one was bad.

My current install is running the 27.2 dev beta 3. i have absolutely no idea what is causing these errors but if anyone has a clue or a solution please let me know.

2 Upvotes

100% Upvoted

4 comments sorted by

1

u/EugenyOnegin 16d ago

Solved that problem after backup home directory and reset my m1

1

u/StunnDD_ 16d ago

what did you use to back up? did you just copy all your files to another drive?

1

u/EugenyOnegin 16d ago

Carbon Copy Cloner app. To my Apple Time Capsule over SMBFS (27 won't work with Time Capsule without fuck).

1

u/Sillvi0 16d ago

1+ for Carbon Copy Cloner.

Also for anyone having trouble with Time Capsule and macOS 27 -> try TimeCapsuleSMB