Cannot downgrade to 10.8

cheesemanpl

macrumors newbie
Original poster
Jun 12, 2013
6
0
I was about do a clean install of 10.8 on my early 2011 15" MBP, but since 10.9 DP came out, I did an upgrade to try it out before wiping everything.

Turns out I can't downgrade now... When loading the installer from a USB stick, the :apple: logo above the spinning wheel changes into a prohibitive sign (slashed circle) after a while, and it never loads. I tried running the installer from the hard drive just to see if it runs, but got the "software cannot be installed on this computer" error. So I wiped my hard drive, but I still keep getting the prohibitive sign.

Any ideas why this could be happening? Could the 10.9 installer have changed the EFI somehow? Is there any way to force the 10.8 installer to load? I'm currently stuck with a largely non-functional system, as some critical apps don't run or keep crashing on 10.9...

EDIT: By downgrading I mean doing a clean install, not installing over the existing system.
 
Last edited:

matt2053

macrumors 6502a
Jul 8, 2012
549
100
I successfully erased my drive and installed 10.8 after having been on 10.9.

Do you have filevault enabled?
 

cheesemanpl

macrumors newbie
Original poster
Jun 12, 2013
6
0
Tried resetting the PRAM, hasn't helped, unfortunately...

EDIT: I don't have FileVault enabled.
 

Jovian9

macrumors 68000
Feb 19, 2003
1,955
99
Planet Zebes
Have you tried booting into recovery (cmd-r) and using disk utility to wipe the hard drive? After that reinstall Mountain Lion from the built-in recovery option.
 

cheesemanpl

macrumors newbie
Original poster
Jun 12, 2013
6
0
The problem is I now have a 10.9 recovery partition instead of a 10.8 one...

I've found some more info on the prohibitive sign icon, and incompatible internal components could be the cause. I have swapped my SuperDrive for an Optibay and installed new RAM since the system was last installed. Do you think temporarily removing the Optibay or swapping the RAM could help?
 

digitalfx

macrumors 6502a
Jul 18, 2007
619
104
This is correct . Same issue here.
I installed 10.9 on rMBP and had a flaky install where it would just loop to log in screen.

So I tried doing a clean install back to ML and I get the same symbol

I can restore a TM backup, but it won't let me do a clean install

I also have the 10.9 restore now, so no love returning to ML short of a TM restore
 

bibyfok

macrumors 6502
Jun 14, 2012
335
6
France
Before installing 10.9 you should have done a clone using CCC, which backups the recovery partition…
Now you have to use a USB/CD with 10.8 on it to boot, use diskutil to repartition (1 partition) and format (to break the 10.9 recovery)
Then you install 10.8 and restore from TimeMachine.

Never install a beta, especially OS, when you don't know how to restore…

(I managed to restore by formatting and restoring with CCC: Boot from the clone and copy from the clone to the internal)
 

cheesemanpl

macrumors newbie
Original poster
Jun 12, 2013
6
0
Now you have to use a USB/CD with 10.8 on it to boot, use diskutil to repartition (1 partition) and format (to break the 10.9 recovery)
Thanks! It turns out it was the 10.9 recovery partition that prevented the installer from loading. I repartitioned the drive instead of just wiping the main partition and everything loads smoothly now.
 

maflynn

Moderator
Staff member
May 3, 2009
65,063
30,991
Boston
^^ That's good to know, I was wondering if the recovery partition was the cause.

When I'm messing with 10.8 and wanting a clean install I make sure the recovery partition is removed. I wish apple would show it, just so we know its there (or not).
 

bibyfok

macrumors 6502
Jun 14, 2012
335
6
France
^^ That's good to know, I was wondering if the recovery partition was the cause.

When I'm messing with 10.8 and wanting a clean install I make sure the recovery partition is removed. I wish apple would show it, just so we know its there (or not).
Just use the partition tool to do "1 partition" and the recovery will be removed ;)
 

maflynn

Moderator
Staff member
May 3, 2009
65,063
30,991
Boston
That's what I do, but since its a real partition it would be nice to see it. Apple should trust its customers a little more :)
 

lcmazza

macrumors regular
Apr 3, 2012
213
0
That's what I do, but since its a real partition it would be nice to see it. Apple should trust its customers a little more :)
You can unhide this partition, but that's not so straightforward as opening Disk Utility like you always do. Anyway, if the user messes up the recovery partition, then Apple support gets a lot more complicated. :D
 

HenryDJP

macrumors 603
Nov 25, 2012
5,084
829
United States
That's what I do, but since its a real partition it would be nice to see it. Apple should trust its customers a little more :)
LOL, at least I think that was sarcasm. :D. Just a hunch, but I'll bet many of the MR members installing Mavericks and talking about it here are not Developers. ;)
 

blueroom

macrumors 603
Feb 15, 2009
6,381
25
Toronto, Canada
LOL, at least I think that was sarcasm. :D. Just a hunch, but I'll bet many of the MR members installing Mavericks and talking about it here are not Developers. ;)
It's what I hate about an OS never meant for anyone but software developers; the amount of chatter by impatient toadies who torrented it, buggered their devices and complain about it in the forums.
 

chown33

Moderator
Staff member
Aug 9, 2009
8,496
4,506
Restivus
That's what I do, but since its a real partition it would be nice to see it. Apple should trust its customers a little more :)
For some time, Disk Utility has had a Debug menu. Enable it with this command-line in Terminal:
Code:
defaults write com.apple.DiskUtility DUDebugMenuEnabled 1
Then launch Disk Utility.app and look in the Debug menu.

In at least Mtn Lion and Snow Leopard (which I checked), there is a "Show every partition" menu-item. Choose it and it will gain a checkmark, and the list shows every partition. E.g. disk0s1 is the EFI partition.

One can also use the command-line to list every partition:
Code:
diskutil list
 

Tubamajuba

macrumors 68020
Jun 8, 2011
2,070
2,008
here
It's what I hate about an OS never meant for anyone but software developers; the amount of chatter by impatient toadies who torrented it, buggered their devices and complain about it in the forums.
Some people do complain... but I personally have no problem with people asking for help if they don't whine and act as if their problem is Apple's fault. The OP here was inquisitive, not demanding. I appreciate that kind of attitude, as it's sorely lacking on the internet.
 

Chairman Plow

macrumors regular
May 15, 2008
216
1
CT
I have a thumb drive set up as my backup ML installer. Powered up while holding the option key to boot from the USB stick, and used Disk Utility to erase the hard drive (getting rid of the 10.9 recovery in the process). Fresh install of ML and back in business. :cool:
 

SantaRosa2.2

macrumors regular
Mar 7, 2012
221
3
Somewhere in Florida
I have a thumb drive set up as my backup ML installer. Powered up while holding the option key to boot from the USB stick, and used Disk Utility to erase the hard drive (getting rid of the 10.9 recovery in the process). Fresh install of ML and back in business. :cool:
That's how you do it. Then if you kept your last Mountain Lion Backup you simply use Migration Assistant to recover your previous state in Mountain Lion. :cool:
 

r0k

macrumors 68040
Mar 3, 2008
3,612
73
Detroit
I downloaded Mavericks and decided to install it in a Virtualbox. I found out THAT wasn't going to work so I had to clean stuff off a "spare" USB drive I had sitting around so I could install it on that thing. But before I did anything else, I created a 10.9 install USB stick. I don't know why Apple is making it harder for us to make our own sticks. It's frustrating.

I had to go in and change finder's settings to show hidden files. I then had to go find "base system.dmg" and restore THAT to a usb stick instead of restoring the entire installESD.dmg. As if this wasn't enough, I had to go delete a sym link to the packages directory and drag and drop the real packages directory where the sym link had been. Sorry I'm not in front of my MBP so these steps are from memory. If you google for Mavericks USB I'm sure you'll find the real instructions.

Anyway, I bring this up to remind you a developer preview OS should NEVER be installed over your "real" OS. These things can be buggy and who knows, they might be time bombed and you'll be faced with trying to buy the real OS only to find the app store in the DP is broken and you can't buy it. :eek:

I'm glad I found this thread as sooner or later I'll want to wipe that "spare" drive and make it bootable for some other OS I want to play with. I'd much rather play with DP OSs in a Virtualbox than devote real hardware to them.

If anyone's thinking of tinkering with iOS 7, think twice as Apple warns you can NOT roll back to iOS 6. It probably has something to do with the new kill switch technology built into iOS7. Allowing a roll-back to iOS6 might provide a thief a back door to get the device in a sellable state.
 

bcaslis

macrumors 68020
Mar 11, 2008
2,165
190
You can roll back to iOS6 from iOS7. This is a standard disclaimer that Apple says with every iOS release. This is to the firmware being updated and there is chance it could make the previous OS not work. Apple doesn't guarantee rolling back to work, but they don't do anything to prevent it.
 

HenryDJP

macrumors 603
Nov 25, 2012
5,084
829
United States
I downloaded Mavericks and decided to install it in a Virtualbox. I found out THAT wasn't going to work so I had to clean stuff off a "spare" USB drive I had sitting around so I could install it on that thing. But before I did anything else, I created a 10.9 install USB stick. I don't know why Apple is making it harder for us to make our own sticks. It's frustrating.

I had to go in and change finder's settings to show hidden files. I then had to go find "base system.dmg" and restore THAT to a usb stick instead of restoring the entire installESD.dmg. As if this wasn't enough, I had to go delete a sym link to the packages directory and drag and drop the real packages directory where the sym link had been. Sorry I'm not in front of my MBP so these steps are from memory. If you google for Mavericks USB I'm sure you'll find the real instructions.

Anyway, I bring this up to remind you a developer preview OS should NEVER be installed over your "real" OS. These things can be buggy and who knows, they might be time bombed and you'll be faced with trying to buy the real OS only to find the app store in the DP is broken and you can't buy it. :eek:

I'm glad I found this thread as sooner or later I'll want to wipe that "spare" drive and make it bootable for some other OS I want to play with. I'd much rather play with DP OSs in a Virtualbox than devote real hardware to them.

If anyone's thinking of tinkering with iOS 7, think twice as Apple warns you can NOT roll back to iOS 6. It probably has something to do with the new kill switch technology built into iOS7. Allowing a roll-back to iOS6 might provide a thief a back door to get the device in a sellable state.
Maybe it would be to your benefit if you were a real developer rather than tormenting and living to tell us about it here. :rolleyes:
 

alexking93

macrumors newbie
Jun 15, 2013
1
0
I'm Dumb

Alright - I did it.

I installed the DP of Mavericks on my system and now I can't downgrade. It's so incompatible right now and my machine is running slower.

How can I go about downgrading this?

I have Mountain Lion in the Mac App Store as well is Disk Images of Mountain Lion.

Really appreciate any help!