I upgraded to Mac OS Monterey and it immediately broke Symantec Endpoint Protection and killed my LAMP server. I'm going to downgrade to MacOS Big Sur. Do these instructions work or can I just get Big Sur from the App Store and install?
iMac 21.5″, macOS 10.13
Thank you. I went through the entire process documented here: https://mackeeper.com/blog/downgrade-macos-monterey-to-big-sur/ and all went well. It took quite a while, as specified, but went without a hitch. Warning to those that do: make sure you have a current day Time Machine backup before doing the downgrade.
Unfortunately, after all the work downgrading, Symantec Endpoint Protection (software I'm licensed for) cannot be installed. I'm assuming it no longer works on any Mac OS > 10.x.
These methods should work, but you'll need to Erase the Drive before installing.
And... I would advise against anything from Symantec or hints at the name Norton if it did work.
Mac OS Monterey "Upgrade"
