Need Help installing an older version of Sierra on external drive

[Apple_Robert]

On my 2017 iMac, I have Sierra 10.12.6 installed (it came with the Mac). I am trying to install Sierra 10.12.049 (Version 12.0.49 (1249) onto an external drive so that I can run a specific program that is not compatible with 12.10.6.

When I try to boot via option and pick the install USB, I get the white stop symbol.

If I try to start the install from the iMac, all the drives options are grayed out. I get the error message that the blank USB drive that I want to install and run Sierra 12.0.49 from already has Sierra installed, which it doesn't.

My ultimate goal is to get the older version of Sierra on an external drive, make a clone of it with CCC (for safety purposes) and use the external drive to boot into the program I want to use, when needed.

@Weaselboy or anyone else... Do you happen to know a workaround for this problem?

 

[Weaselboy]

When I try to boot via option and pick the install USB, I get the white stop symbol.

Sounds like something is wrong with your installer USB key. Are you sure you used the correct Terminal string to make the USB key?

sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --applicationpath /Applications/Install\ macOS\ Sierra.app

Just change MyVolume here to whatever yours is.

 

[Apple_Robert]

Sounds like something is wrong with your installer USB key. Are you sure you used the correct Terminal string to make the USB key?

sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --applicationpath /Applications/Install\ macOS\ Sierra.app

Just change MyVolume here to whatever yours is.

That is the exact command I used.

Is the white stop sign because my Mac didn't come with 10.12.0?

 

[Weaselboy]

That is the exact command I used.

Is the white stop sign because my Mac didn't come with 10.12.0?

I overlooked that... I think that's it.



This from Everymac shows it came with 10.12.4, so yeah... I don't think 10.12.0.x is going to have the right drivers and all.

 

[Apple_Robert]

I overlooked that... I think that's it.

View attachment 825741

This from Everymac shows it came with 10.12.4, so yeah... I don't think 10.12.0.x is going to have the right drivers and all.

So, no way to install it on an external drive?

 

[DeltaMac]

It's easy to confuse the installer.app version with the system version that installer will produce.
There is NO Sierra version 10.12.049 - but I think it is an installer that will result in macOS 10.12.1 or 10.12.2
You said your Mac came with 10.12.6. It would have come from Apple with either 10.12.4 or 10.12.5 - and most users would update the original almost immediately. THAT doesn't matter so much.
BUT, 10.12.1 or 10.12.2 (or older) won't work, it won't boot, and will give you that "prohibited" symbol. That version is too old.
If you need to run older software, not compatible with your newer Mac, then you need an older Mac to use it (or a method to run an older version of macOS through a VM system) which might be a big adventure to get that to work.
So, with all that in mind --- Can you tell what software you need to use that runs on an older Sierra version, but not on your up-to-date Sierra system? I'm curious which app you want to use (?)

It also makes no difference whether it gets installed on an internal, or external drive. Your newer Mac won't boot to a system that is older than the system that Apple originally shipped on your model Mac.

 

[Apple_Robert]

It's easy to confuse the installer.app version with the system version that installer will produce.
There is NO Sierra version 10.12.049 - but I think it is an installer that will result in macOS 10.12.1 or 10.12.2
You said your Mac came with 10.12.6. It would have come from Apple with either 10.12.4 or 10.12.5 - and most users would update the original almost immediately. THAT doesn't matter so much.
BUT, 10.12.1 or 10.12.2 (or older) won't work, it won't boot, and will give you that "prohibited" symbol. That version is too old.
If you need to run older software, not compatible with your newer Mac, then you need an older Mac to use it (or a method to run an older version of macOS through a VM system) which might be a big adventure to get that to work.
So, with all that in mind --- Can you tell what software you need to use that runs on an older Sierra version, but not on your up-to-date Sierra system? I'm curious which app you want to use (?)

It also makes no difference whether it gets installed on an internal, or external drive. Your newer Mac won't boot to a system that is older than the system that Apple originally shipped on your model Mac.

Thank you both for replying. Disappointing news. I have spent my weekend trying to get this to work. Live and learn.

I was wanting to use a program I used in the past to 'modify a limiting built in factor, that doesn't allow you to use iTunes purchases on a Plex home sever.' I don't want to get in possible trouble mentioning the name.

I tried Parallels just now and it shows 10.12 (16a323) as being installed on the VM. Don't know if that is completely accurate.

 

[DeltaMac]

Ah, OK.
I suppose you have tried to contact the developer to verify that macOS compatibility?
I suspect it's not really the macOS system itself, but likely an update to iTunes that might have locked out access that program needs to do its work. Either way, that doesn't really matter if the program won't work now.