Got a tip for us?
Let us know
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Possible to downgrade from High Sierra to El Capitan?
- Thread starter Wozza2010
- Start date
- Sort by reaction score
Yeah it very much depends on what model of Mac this is. If it was initially release during or before the El Cap era it's fine. If it came out after El Cap was replaced it's a no-go
You may need to reset the date of the computer before you do the erase and install.
El Capitan. no packages were eligible for… - Apple Community
Last edited:
OP wrote:
"I have managed to make a bootable USB drive with El Capitan. Just wondering if it is safe to wipe and downgrade?"
Come back and let us know how it went, ok...?
Something you should be aware of:
Some older installers will refuse to work, due to Apple's cancelling of some kind of "certificate" for them. There's NOTHING WRONG with the OS, just a stupid move that Apple made.
If the install "chokes", there's a trick that might (or might not) help.
It's worth a try.
You have to SET BACK THE INTERNAL CLOCK to about January 2018.
Also, turn off the "set date and time automatically" option in the date & time preference pane.
If the install now goes through ok, just reset your date and time when done.
"I have managed to make a bootable USB drive with El Capitan. Just wondering if it is safe to wipe and downgrade?"
Come back and let us know how it went, ok...?
Something you should be aware of:
Some older installers will refuse to work, due to Apple's cancelling of some kind of "certificate" for them. There's NOTHING WRONG with the OS, just a stupid move that Apple made.
If the install "chokes", there's a trick that might (or might not) help.
It's worth a try.
You have to SET BACK THE INTERNAL CLOCK to about January 2018.
Also, turn off the "set date and time automatically" option in the date & time preference pane.
If the install now goes through ok, just reset your date and time when done.
I mean the core of what Apple is doing here with the certificate is actually really sensible. What's stupid is the error message you get when it fails to go through, but signing updates and installers with expiring certificates for security and authenticity does make sense. The correct error reporting should just be to pop a dialog box for the user to say "Yes, I acknowledge that the certificate has expired and you cannot verify the validity of the package in any other way - Install anyway", instead of modifying the clock
I agree it does not make a lot of sense to have a timed signed certificate that can be fooled by simply back dating the system clock.
Considering your Mac model, yeah it's perfectly fine
You may need to reset the date of the computer before you do the erase and install.
El Capitan. no packages were eligible for… - Apple Community
discussions.apple.com
When do I reset the time? Prior to rebooting for the install or during the install?
Change the date/time and disable automatic setting of date/time prior to booting from the installer.
Last edited: