Is it safe to go back to Mojave on MBP Pro with T2 updated to latest firmware under Catalina 10.15.5 Beta?
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Go back to Mojave
- Thread starter sashavegas
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I don't see anything in Apple's documentation that states you wouldn't be able to go back to a prior version of macOS on a T2 MBP that originally shipped (spec-wise) with High Sierra or Mojave.
Some thoughts...
You're going to have to erase THE ENTIRE DRIVE first.
You're also going to have to use a special version of internet recovery. The "regular" version will probably just re-install Catalina.
So, do this:
1. BACK UP the internal drive to an external drive. I recommend CarbonCopyCloner or SuperDuper. Both are free to download and use for 30 days.
2. Boot to this version of internet recovery that will allow you to install the earliest version of the OS that shipped with your MB:
shift option command R at boot.
3. Open disk utility and choose "show all devices" from the view menu (VERY important that you do this)
4. ERASE the internal drive to APFS, GUID partition format.
5. Quit disk utility and open the OS installer, begin the install. This will involve one or more reboots, the screen may go dark for a minute or two, you may see one or more "progress bars" during the install.
6. When the install is done, you should see the initial setup screen "choose your language". Begin setup.
7. You can try to use setup assistant to "migrate back" your pre-existing apps and data, but not sure if that will work because you're going from "newer" back to "older". If it DOESN'T work, then you'll have to "move stuff over by hand".
THAT'S WHY you want a cloned backup that will mount up right "in the finder".
You're going to have to erase THE ENTIRE DRIVE first.
You're also going to have to use a special version of internet recovery. The "regular" version will probably just re-install Catalina.
So, do this:
1. BACK UP the internal drive to an external drive. I recommend CarbonCopyCloner or SuperDuper. Both are free to download and use for 30 days.
2. Boot to this version of internet recovery that will allow you to install the earliest version of the OS that shipped with your MB:
shift option command R at boot.
3. Open disk utility and choose "show all devices" from the view menu (VERY important that you do this)
4. ERASE the internal drive to APFS, GUID partition format.
5. Quit disk utility and open the OS installer, begin the install. This will involve one or more reboots, the screen may go dark for a minute or two, you may see one or more "progress bars" during the install.
6. When the install is done, you should see the initial setup screen "choose your language". Begin setup.
7. You can try to use setup assistant to "migrate back" your pre-existing apps and data, but not sure if that will work because you're going from "newer" back to "older". If it DOESN'T work, then you'll have to "move stuff over by hand".
THAT'S WHY you want a cloned backup that will mount up right "in the finder".
when i put packet sniffer, i can clearly see what syspolicyd doing ....
i stop it now with little snitch, but that is not a solution
i stop it now with little snitch, but that is not a solution
I had trouble accessing recovery after the downgrade, definitely test this once you're done.
