Can't install macos sierra

[darkweather]

I was using macos sierra public beta on external usb 3.0 usb.
First i try to boot in recovery and reinstall macos sierra. but after installation progress imac boot to prohibitory sign.
Then, I downloaded macos sierra from app store and when installed it, imac booted with prohibitory sign.
After that i made and bootable usb and try to install it but again prohibitory sign.
Then, I boot from internal drive and i used carbon copy cloner and copied internal drive to ssd (el capitan).
After that i again try to install macos sierra to ssd with el capitan. but same thing happaned and can't boot with prohibitory sign.
Now, I can use external ssd with (corbon copied) os x el capitan but cannot update to sierra.
What can i do?

 

[RumorzGuy]

I was using macos sierra public beta on external usb 3.0 usb.
First i try to boot in recovery and reinstall macos sierra. but after installation progress imac boot to prohibitory sign.
Then, I downloaded macos sierra from app store and when installed it, imac booted with prohibitory sign.
After that i made and bootable usb and try to install it but again prohibitory sign.
Then, I boot from internal drive and i used carbon copy cloner and copied internal drive to ssd (el capitan).
After that i again try to install macos sierra to ssd with el capitan. but same thing happaned and can't boot with prohibitory sign.
Now, I can use external ssd with (corbon copied) os x el capitan but cannot update to sierra.
What can i do?

Are you conducting a clean install? That may be your best option at this point.

Make sure that you back up anything that you don't want to lose first.

 

[darkweather]

Are you conducting a clean install? That may be your best option at this point.

Make sure that you back up anything that you don't want to lose first.

yes. i formatted the external ssd and than tried to reinstall with usb installer. but it failed again.

 

[RumorzGuy]

yes. i formatted the external ssd and than tried to reinstall with usb installer. but it failed again.

I have zero experience with SSDs, so I really don't know what to tell you. But it does sound like some kind of incompatibility exists between Sierra and your SSD. Is it possible that just that particular brand doesn't work with Sierra? I don't have any SSDs, but I have successfully used a partition on my WD external USB hard drive several times now to install Sierra on my iMac's internal hard drive. From what I have read on this forum, sometimes certain devices -- including flash drives -- fail to work when it comes to Sierra, and you to need to switch to a different one. I have read where some folks have had to try two or three different flash drives before they can successfully build a Sierra installer. Whether or not that same problem might exist with SSDs, I really don't know.

 

[darkweather]

I have zero experience with SSDs, so I really don't know what to tell you. But it does sound like some kind of incompatibility exists between Sierra and your SSD. Is it possible that just that particular brand doesn't work with Sierra? I don't have any SSDs, but I have successfully used a partition on my WD external USB hard drive several times now to install Sierra on my iMac's internal hard drive. From what I have read on this forum, sometimes certain devices -- including flash drives -- fail to work when it comes to Sierra, and you to need to switch to a different one. I have read where some folks have had to try two or three different flash drives before they can successfully build a Sierra installer. Whether or not that same problem might exist with SSDs, I really don't know.

Yes. But what interesting is i used this ssd even with all public betas with no problem.

 

[RumorzGuy]

Yes. But what interesting is i used this ssd even with all public betas with no problem.

I don't know exactly how SSDs work, but when you format the drive, are you formatting the entire drive, or just a partition on the drive? If it were a regular hard drive -- as opposed to a SSD -- and you were trying to format the entire drive, I believe you would need to make sure that you choose the GUID partition scheme. It just seems like there is something very basic here that you are missing or overlooking.

 

[Fishrrman]

My suggestions:
Since you already have a CCC backup with El Capitan...

- Boot from your CCC backup.

- Go to the App Store and download a clean copy of the Sierra installer if you don't have that available (it should download to the applications folder).

- Take a USB flashdrive of at least 16gb capacity, and use Terminal to create a bootable, standalone Sierra install drive.

- Now, shut down and disconnect the CCC backup.

- Boot from the USB installer

- Use Disk Utility to re-initialize the internal drive

- Now, launch the Sierra installer and let it install an entirely new copy onto the internal drive.

- At the close of the install, setup assistant will ask if you want to migrate data from another drive. Connect the CCC backup and use that as your source for migration.

- Setup assistant should "bring over" your accounts, apps, settings and data.

- When done, reboot from internal drive...

 

[darkweather]

My suggestions:
Since you already have a CCC backup with El Capitan...

- Boot from your CCC backup.

- Go to the App Store and download a clean copy of the Sierra installer if you don't have that available (it should download to the applications folder).

- Take a USB flashdrive of at least 16gb capacity, and use Terminal to create a bootable, standalone Sierra install drive.

- Now, shut down and disconnect the CCC backup.

- Boot from the USB installer

- Use Disk Utility to re-initialize the internal drive

- Now, launch the Sierra installer and let it install an entirely new copy onto the internal drive.

- At the close of the install, setup assistant will ask if you want to migrate data from another drive. Connect the CCC backup and use that as your source for migration.

- Setup assistant should "bring over" your accounts, apps, settings and data.

- When done, reboot from internal drive...

thank you but i think i didn't express the problem exactly.
- i don't have ccc backup. i just downloaded the trial version of ccc.
- then i copied internal drive to my external ssd by ccc.
- now i have two systems 1) internal hdd with el capitan and 2) external ssd with el capitan
- i don't want to update internal drive to sierra because i think it's already very slow and sierra will make it slower.
- i just want to update or reinstal/clean install to SSD to macos sierra (that's no problem, i can delete everything on ssd)

 

[Fishrrman]

OP wrote:
"- i just want to update or reinstal/clean install to SSD to macos sierra (that's no problem, i can delete everything on ssd)"

Then, do it this way:

- Use Disk Utility to erase the external SSD.

- Go to the App Store and download a clean copy of the Sierra installer if you don't have that available (it should download to the applications folder).

- Take a USB flashdrive of at least 16gb capacity, and use Terminal to create a bootable, standalone Sierra install drive.

- Shut down computer. Reboot to bootable installer (on flash drive)

- When you run the installer, it will ask WHICH DRIVE you want to install onto.

- Select external SSD and let the installer take it from there.

 

[darkweather]

OP wrote:
"- i just want to update or reinstal/clean install to SSD to macos sierra (that's no problem, i can delete everything on ssd)"

Then, do it this way:

- Use Disk Utility to erase the external SSD.

- Go to the App Store and download a clean copy of the Sierra installer if you don't have that available (it should download to the applications folder).

- Take a USB flashdrive of at least 16gb capacity, and use Terminal to create a bootable, standalone Sierra install drive.

- Shut down computer. Reboot to bootable installer (on flash drive)

- When you run the installer, it will ask WHICH DRIVE you want to install onto.

- Select external SSD and let the installer take it from there.

i did exactly the same but after restart imac stuck with prohibitory sign...

 

[darkweather]

here is the ss of the ssd after stuck with prohibitory sign. (i boot the mac from internal hdd)
https://i.snag.gy/kFXyto.jpg

 

[idoccurt]

on a supported mac?

 

[borgusio]

I am trying to install sierra from a usb drive on my mac mini 2012.

I did the same process I did with older versions of the os:
- downloaded sierra from the app store
- moved it to the usb stick with terminal
- restart my mac mini and keep the alt key pressed
- choose the usb drive as boot drive
- the screen with the apple showss up and the installer starts loading

-> before finishing to load the installer a prohibitory sign shows up and I cannot do anything!
I also downloaded sierra a second time to make sure that the usb is not corrupted. As I said, nothing changed from the installation process of el capitan.

Any ideas?

 

[tywebb13]

- moved it to the usb stick with terminal

How exactly did you move it with terminal?

One should do it with this (if your usb is called Untitled):

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

This doesn't just move it to the usb, but also puts hidden files there too making it bootable.

So just moving it there isn't enough to make it bootable.

 

[borgusio]

How exactly did you move it with terminal?

One should do it with this (if your usb is called Untitled):

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

Thanks for your suggestion, but I can confirm that the method used is the correct one, the one you mentioned. As I wrote already: I used the same method which I used since several years on many macs including this mac and my other macs (mac mini 2011, macbook pro 13 2012, macbook 12).

I can also confirm that the usb installer is properly recognised and boots without any issue (the apple shows up and the loader starts working). At round about 2/3 of the process it stops.

I tried also a pram reset.

Ideas anyone?

 

[borgusio]

Hello everyone, sorry for insisting... unfortunately the admins removed my original thread and merged it with this one which title is too generic.

I am stuck with an otherwise perfectly fine Mac mini running El Capitan and not being able to install Sierra due to the fact that I get a prohibitory sign during the loading phase of the installer...

Your help would be very much appreciated.

 

[hwojtek]

Create an install USB stick, boot from it.

 

[DeltaMac]

So, you can't boot to the USB installer?

If you always get the "prohibited" sign when trying to boot to the USB installer, then you either have a corrupted USB stick, or the installer is NOT copied properly to make the USB drive bootable.

Try to make the USB installer again, double check that you are following good steps, and that your terminal commands are correct. If all of that is good, and you STILL can't boot to that USB flash drive, then try a different flash drive.

Something else to try:
I use DiskMakerX to create the bootable flash drive. It always works for me, particularly when making a Sierra USB installer while booted to El Capitan.

 

[borgusio]

Hello DeltaMac, thanks for your help.
The weird thing is that if I create the stick with the El Capitan installer, it works. With Sierra (downloaded three times) it doesn't.