Downgrade from Catalina

purpleinnej

macrumors member
Original poster
Feb 8, 2010
62
2
Yigo, GU
Goal: Run Mac OS Mojave (10.14)
Current OS: Catalina (10.15)
Previous OS: Sierra (10.12)
Backstory: Was running Mac OS Sierra (10.12). Held on to it for a long time to avoid switching from iPhoto to Photos, but finally gave in, made that switch, and upgraded to Catalina (10.15). Immediately regretted it. Mostly because Office 2011 is 32-bit and not supported in Catalina.

Plan A: Use Time Machine to go back to just before installing Catalina (already saved edited files to an external drive)
Failed because: Restore button is grayed out

Plan B: Download Mojave from App Store and install it
Failed because: App store won't let you downgrade. Just says something to the effect of "you're running a newer OS, so you can't do this."

Plan C: Make a bootable installer per instructions here: https://www.macworld.co.uk/how-to/mac-software/downgrade-macos-3581872/#bootable
Failed because: When I try to install Mojave from the bootable installer, I get an error about not installing Mojave on a hard drive already running Catalina. I've also tried changing the startup disc to the bootable installer disc, but get an error regarding HFS and APFS.

Really, I don't understand at all why Time Machine won't let me restore it to the date I choose. What's the point of even having it if I can't use its most basic function?? I'm really ripping my hair out here. I would obviously rather not wipe my hard drive, but if I do, will I then be able to use Time Machine to restore it to the date I choose? What if that doesn't work? I have my Time Machine backups, and I can backup files easily, but not sure about backing up apps, etc. outside of Time Machine if I wipe it and can't use Time Machine to restore it.
 
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Peadogie

macrumors regular
Aug 4, 2019
153
83
Georgia, USA
You can get the Mojave installer Here:
https://apps.apple.com/app/id1398502828
If you don't see a "GET" button go to /Library/Updates in the Finder and delete any update files have that been previously downloaded.
AFAIK you have to wipe the drive or you will get an error saying that Mojave is to old to install.
You should then be able to 'restore' (including Applications) from your 'Time Machine' backup using the 'Set Up Assistant' in the install process.
To avoid the "Update to Catalina" badge in 'System Preferences/Dock' see my post here:
 
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Cleanedupmyact

macrumors newbie
May 11, 2019
4
0
I wiped the Catalina drive, then tried to install Mojave through Internet Recovery. That failed with different error codes (3101, 1008 etc.), both wired and wifi. Then installed Mojave from a USB Installer I had prepared many moons ago.
However, it appears the Catalina downgrade is not very graceful because after spending almost a day on the above activities, I found that while the OS itself worked fine and my apps worked fine, somehow the recovery partition was borked and my Mac wouldn't boot into recovery mode no matter what. So ok, I thought I can always run recovery from usb, lemme make a new USB Installer with 10.14.6. I made 3 sticks, 2 using createinstallmedia and one with Disk Creator, strangely none of them worked.
At this point, I was ready to give up and tried Internet Recovery again. It worked now and am back to Catalina which is OK. No, I did not have a time machine backup because I keep my data in the cloud.
 

lambertjohn

macrumors 65816
Jun 17, 2012
1,115
1,087
Not surprised at all the problems going back to Mojave. Apple makes it as difficult as possible to downgrade operating systems. They absolutely don't want you going backwards with "upgrades."
 

chucker23n1

macrumors 68030
Dec 7, 2014
2,932
3,869
Not surprised at all the problems going back to Mojave. Apple makes it as difficult as possible to downgrade operating systems. They absolutely don't want you going backwards with "upgrades."
They don't really care that much. They just don't prioritize it in QA.
 

sashavegas

macrumors newbie
Jul 11, 2018
11
1
You need to wipe HD(under disk Utility->show all device), and during installation turn wifi off, open terminal and type "date 0901000019" than back to install screen and install Mojave.
 

Fishrrman

macrumors P6
Feb 20, 2009
18,271
6,131
Important question:
Do you have a backup from your earlier install that has not been over-written since you installed Catalina?
This will make it easier to "get back".

Also...
I believe you'll need to COMPLETELY ERASE your internal drive before you re-install a previous OS.

Do you happen to have an EXTERNAL drive that you could use as a "test drive" to do an OS install to?

You are just "one more user" posting in this forum who "upgraded" to Catalina without a proper backup (a "proper backup" would be a BOOTABLE CLONED BACKUP created with CarbonCopyCloner or SuperDuper), and then found himself "up xxxx creek without a paddle to get back".... (sigh)
 
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purpleinnej

macrumors member
Original poster
Feb 8, 2010
62
2
Yigo, GU
Important question:
Do you have a backup from your earlier install that has not been over-written since you installed Catalina?
This will make it easier to "get back".

Also...
I believe you'll need to COMPLETELY ERASE your internal drive before you re-install a previous OS.

Do you happen to have an EXTERNAL drive that you could use as a "test drive" to do an OS install to?

You are just "one more user" posting in this forum who "upgraded" to Catalina without a proper backup (a "proper backup" would be a BOOTABLE CLONED BACKUP created with CarbonCopyCloner or SuperDuper), and then found himself "up xxxx creek without a paddle to get back".... (sigh)

I THOUGHT I had a backup because I was using Time Machine religiously. I didn't realize that wouldn't suffice as a usable backup. I never had Mojave on my system; went straight from Sierra to Catalina.

I definitely have a hard drive I can use, but I'm not sure how that helps or what to do.

Maybe I'm just stuck with Catalina and all its problems. I am not really sure what the best course is, at this point. Is there a way to semi-backup, i.e. just copy files and apps, etc. to an external drive, wipe the hard drive, somehow install Sierra or Mojave, then copy my files and apps back from the external drive?
 

Riwam

macrumors 65816
Jan 7, 2014
1,079
241
Basel, Switzerland
I THOUGHT I had a backup because I was using Time Machine religiously. I didn't realize that wouldn't suffice as a usable backup. I never had Mojave on my system; went straight from Sierra to Catalina.

I definitely have a hard drive I can use, but I'm not sure how that helps or what to do.

Maybe I'm just stuck with Catalina and all its problems. I am not really sure what the best course is, at this point. Is there a way to semi-backup, i.e. just copy files and apps, etc. to an external drive, wipe the hard drive, somehow install Sierra or Mojave, then copy my files and apps back from the external drive?
Too many Mac users believe that TimeMachine is enough as a backup safety measure and only when they get into some serious trouble they realize that TimeMachine is only half of the needed backup policy. The other half is to keep bootable clones of the MacOS used and even of previous MacOS if upgraded
Half a money bill cannot be used to pay for anything. You need the other half.
 

Fishrrman

macrumors P6
Feb 20, 2009
18,271
6,131
"I definitely have a hard drive I can use, but I'm not sure how that helps or what to do."

OK, I'm going to offer you "a way forward", which you can try if you like.

You'll need the external drive.
This will HURT NOTHING on your internal drive (that's why I'm suggesting it).
PRINT OUT this post if you intend to try it, then CHECK OFF each step.

a. Power down, all the way off
b. Connect the spare external drive you have.
c. Press the power on button, and then IMMEDIATELY hold down:
Shift-OPTION-Command-R
And KEEP HOLDING THEM DOWN until the spinning globe appears.
This should boot you into a special version of internet recovery that will install the original OS that your Mac shipped with.
DON'T WORRY about WHICH OS this is. You just want to get something OTHER THAN Catalina up-and-running.
d. You may need your wifi password if you connect wirelessly
e. Do you eventually get into internet utilities?
If so, GOOD, let's move further on.
f. Open Disk Utility.
g. Is there a "view" menu? If there is, see if it offers the option to "show all devices", and choose this if available (if it's NOT available, don't worry about it).
h. Now, look at the device/volume list on the left. Do you see the listing for the external drive?
i. If so, click on the line that represents the physical external drive, then ERASE IT to "Mac OS extended with journaling enabled", GUID partition format
WARNING! DO NOT erase the INTERNAL drive!
j. Once the external drive is erased, close Disk Utility and open the OS installer
k. Begin to "click through" the install process, BUT...
l. ... when asked WHERE you want to install, CHOOSE THE EXTERNAL DRIVE
m. OK, let things go and see if the installer will install a copy of the OS onto the external drive. The Mac may reboot one or more times in this process.
n. Does the install complete? If so, you'll see the initial setup screen (choose your language).
o. Follow setup and create a basic account for yourself. I would suggest that you DO NOT "migrate anything" at this point.

WHY WE ARE DOING THIS:
The whole purpose here is to create an independently-bootable volume THAT IS NOT CATALINA.
The reason I suggest the external drive is because it will "hurt nothing" on the internal drive.

OK, get to it...!
 

purpleinnej

macrumors member
Original poster
Feb 8, 2010
62
2
Yigo, GU
"I definitely have a hard drive I can use, but I'm not sure how that helps or what to do."

OK, I'm going to offer you "a way forward", which you can try if you like.

You'll need the external drive.
This will HURT NOTHING on your internal drive (that's why I'm suggesting it).
PRINT OUT this post if you intend to try it, then CHECK OFF each step.

a. Power down, all the way off
b. Connect the spare external drive you have.
c. Press the power on button, and then IMMEDIATELY hold down:
Shift-OPTION-Command-R
And KEEP HOLDING THEM DOWN until the spinning globe appears.
This should boot you into a special version of internet recovery that will install the original OS that your Mac shipped with.
DON'T WORRY about WHICH OS this is. You just want to get something OTHER THAN Catalina up-and-running.
d. You may need your wifi password if you connect wirelessly
e. Do you eventually get into internet utilities?
If so, GOOD, let's move further on.
f. Open Disk Utility.
g. Is there a "view" menu? If there is, see if it offers the option to "show all devices", and choose this if available (if it's NOT available, don't worry about it).
h. Now, look at the device/volume list on the left. Do you see the listing for the external drive?
i. If so, click on the line that represents the physical external drive, then ERASE IT to "Mac OS extended with journaling enabled", GUID partition format
WARNING! DO NOT erase the INTERNAL drive!
j. Once the external drive is erased, close Disk Utility and open the OS installer
k. Begin to "click through" the install process, BUT...
l. ... when asked WHERE you want to install, CHOOSE THE EXTERNAL DRIVE
m. OK, let things go and see if the installer will install a copy of the OS onto the external drive. The Mac may reboot one or more times in this process.
n. Does the install complete? If so, you'll see the initial setup screen (choose your language).
o. Follow setup and create a basic account for yourself. I would suggest that you DO NOT "migrate anything" at this point.

WHY WE ARE DOING THIS:
The whole purpose here is to create an independently-bootable volume THAT IS NOT CATALINA.
The reason I suggest the external drive is because it will "hurt nothing" on the internal drive.

OK, get to it...!

SUCCESS!!! Ish. Lol. Followed these steps (thank you for such detail!) and now have Mavericks running on the external hard drive. Now what??

Side note: when asking where I wanted to install it, the external HD was the only option. Screenshot attached.
 

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Fishrrman

macrumors P6
Feb 20, 2009
18,271
6,131
OK, so you can boot and run your Mac with Mavericks from the external drive?

That's a start.

Now, IMPORTANT QUESTION:
Do you want to GET RID of Catalina?
That can be done, and you can get Mavericks running on the internal drive, if you want.

Once you have done this, you can then upgrade Mavericks to Mojave.
I'm not sure if this can be done "in one step", or if an "incremental upgrade" will be required.

If you want to GET RID of Catalina, the next steps would be:
- Download CarbonCopyCloner version 4 from this page:
- Put it on the Mavericks external drive.
- BOOT FROM the Mavericks drive
- Open Disk Utility and COMPLETELY ERASE the internal drive
- Use CCC to clone the contents of the external drive to the INTERNAL drive.

Now you are booting and running from Mavericks on the internal drive.

That's the next major step, if you want to take it.
 

purpleinnej

macrumors member
Original poster
Feb 8, 2010
62
2
Yigo, GU
Before I do erase my internal drive, what do I do for a backup? That part really concerns me (obviously). I have the time machine backups but it seems like that won’t help me. Is there a way to save just my files and apps without doing a backup that will also save the OS?

I can upgrade the external drive to Sierra or Mojave. I’m thinking upgrade to Sierra then somehow use my existing time machine backup from my pre-Catalina install. Is there a way to use Time Machine from one drive (internal) and apply it to another drive (external)?
 
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Fishrrman

macrumors P6
Feb 20, 2009
18,271
6,131
"Before I do erase my internal drive, what do I do for a backup?"

OK... looking for the way forward here... hmmmm... could be "disk format problems" between Catalina and Mavericks that prevent you from mounting a Catalina backup in Mavericks... how to get around them?

OK... I have a solution that could work, but you're gonna have to run on faith for a little while.

Here's my suggestion:
1. Download CarbonCopyCloner version 5 (not 4, you need 4 with Mavericks) from the CCC download page (URL in earlier post above).
2. You need a SECOND external drive (not the one with Mavericks on it).
3. Boot to Catalina
4. Connect the SECOND drive to the Mac
5. Use Disk Utility to erase it to APFS
6. Use CCC 5 to create a cloned backup of the INTERNAL drive to external drive #2

Now you have a cloned backup of the Catalina install.
Everything that was on the internal drive "is there".
BUT...
I don't think you can mount this drive booted into Mavericks.

You WILL be able to mount it if and when you get your internal drive "up to" Mojave. So you'll have to "put it aside" for a while until you resolve that issue.

This looks to be "your way forward".
Are you beginning to see what happens when you blindly upgrade to a major new version of the OS without taking the necessary precautions beforehand?
 
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purpleinnej

macrumors member
Original poster
Feb 8, 2010
62
2
Yigo, GU
Live and learn! I thought Time Machine was the only backup I needed. Now I know better for next time. Working on moving things around so I have a second empty external drive to move forward. Will update after next steps.
 
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purpleinnej

macrumors member
Original poster
Feb 8, 2010
62
2
Yigo, GU
UPDATE: I tried something before going to the “erase your internal drive” step and I think it may make the next step easier.

External drive was running Mavericks.I upgraded it to Sierra. Was able to use time machine recovery to get it imaged as my pre-Catalina install.

Now the question becomes how to copy what is on the external drive (basically what my internal drive was before I ruined it with Catalina) onto my internal drive, and overwrite the Catalina install there.

Here’s what I’m thinking:
Boot from external drive
Download CarbonCopyCloner 4 (for Sierra)
Shut down and remove external hard drive
Cmd+shift+r to reboot in internet recovery mode
Restore internal hard drive to Mavericks just like I did previously with the external drive
Mount external drive
Use CCC 4 to copy external drive onto internal drive

Will that work? Did I miss anything?
 

purpleinnej

macrumors member
Original poster
Feb 8, 2010
62
2
Yigo, GU
FINAL UPDATE:
I'm grateful for all the advice and steps above. I learned a lot throughout the process and doing the internet recovery OS on an external drive while leaving the internal drive alone made me feel much better about pulling the trigger when it came time to wipe my internal drive.

That being said, if anyone is looking for a bit more direct route to a solution AND YOU HAVE A TIME MACHINE BACKUP TO USE...

shift+cmd+alt+R to boot in Internet Recovery Mode
Erase Macintosh HD using Disk Utility
Reinstall MacOS to revert to the original OS on your Mac
(Upgrade to OS of your Time Machine backup... not sure if this step is necessary but I did it)
Reboot cmd+r to normal recovery mode
Mount drive with Time Machine Backup and follow steps to "Restore from Time Machine Backup"

Could've saved myself a week of starting a process before work, doing a couple of steps in the evening, then setting something up to run overnight. Plus I spent a LOT of time moving files around on hard drives to get one I could safely erase. But, bottom line is I'm back to Sierra, with everything how it should be. Upgrading to Mojave in the near future AFTER doing a proper backup. Thanks for all of your help!
 

ssls6

macrumors 6502a
Feb 7, 2013
543
147
I wiped the Catalina drive, then tried to install Mojave through Internet Recovery. That failed with different error codes (3101, 1008 etc.), both wired and wifi. Then installed Mojave from a USB Installer I had prepared many moons ago.
However, it appears the Catalina downgrade is not very graceful because after spending almost a day on the above activities, I found that while the OS itself worked fine and my apps worked fine, somehow the recovery partition was borked and my Mac wouldn't boot into recovery mode no matter what. So ok, I thought I can always run recovery from usb, lemme make a new USB Installer with 10.14.6. I made 3 sticks, 2 using createinstallmedia and one with Disk Creator, strangely none of them worked.
At this point, I was ready to give up and tried Internet Recovery again. It worked now and am back to Catalina which is OK. No, I did not have a time machine backup because I keep my data in the cloud.
I had the same issue and my Mac has the T2 chip. Does yours?
 

Eliott69

macrumors member
Mar 16, 2019
35
26
[...] made that switch, and upgraded to Catalina (10.15). Immediately regretted it. Mostly because Office 2011 is 32-bit and not supported in Catalina.
... and you went through all that hassle because you wanted to stick to a 10 year old MS Office version? The time you spent on this did cost you more money than the $ 150 for an Office 2019 one-time-purchase...
 

Riwam

macrumors 65816
Jan 7, 2014
1,079
241
Basel, Switzerland
... and you went through all that hassle because you wanted to stick to a 10 year old MS Office version? The time you spent on this did cost you more money than the $ 150 for an Office 2019 one-time-purchase...
Some people have more time to invest in anything they need than money to spend.
One should not judge people one does not know. The value of time is an individual matter.