Downgrade from Sierra to Yosemite

Backup, Backup, Backup no matter what you decide to do.

(a) will going back to yosmite also crash my laptop

without knowing why your Mac crashes, it is impossible to know if it will still crash with Yosemite.

You should really start a new 'Post' (see 'Post' button at the top of this page, and create a new post in the forum associated with the operating system you current have running). In your new post you should include the kernel panic reports (or at least a few of the most recent, to see if there is a trend, or if it is random)

1)

Kernel Panic reports: Finder -> Go -> Go to Folder -> /Library/Logs/DiagnosticReports

<http://support.apple.com/kb/ht2546>

<http://support.apple.com/en-us/HT200553>

The panic report should have "panic" in the file name.

2) also

Please post the EtreCheck output as a "Reply" to this thread

<https://discussions.apple.com/docs/DOC-6174> or <https://etrecheck.com>

Use the EtreCheck "Share" button to "Copy Report" (See the image below)

And then Paste in a "Reply" to this thread.

If, AND ONLY IF, you get the error:

"The message contains invalid characters"

then try posting to PasteBin.com, and give us a PasteBin URL link.

<http://pastebin.com/>

.

EtreCheck is a tool that helps Apple Support Community volunteers debug problems without any access to the troubled computers. Debugging problems can be a difficult task even when the machine is in front of you. Attempting it via a discussion forum is extremely difficult. EtreCheck is a great help that regards.

(b) what are the potential risks of going back to Yosmite

Apple is no longer providing security updates. Otherwise, if you are careful, then not too much

(c) do you have any other solutions for the above (1) and (2)

You should try an SMC reset and an NVRAM reset

<Reset the System Management Controller (SMC) on your Mac - Apple Support>

<How to reset NVRAM on your Mac - Apple Support>

Not sure if this will help, but it will not hurt either

Also seeing the EtreCheck output requested above would be useful.

Again, all of this should be in a new 'Post' in the forum associated with the operating system you are actually using at the moment.

Thank you for the information.

Please find below a link to the new thread on this issue, where I have attempted all the items you have listed above (except C). Appreciate your feedback.

Re: Sierra to Yosemite downgrade

HI,

I was wondering if you could help me. My Macbook air (2014 model) came with Yosmite. There were no issues. But after I did a software update (I think) i have experienced 2 main issues:

(1) No sound after sleep: Whenever I on my laptop after it goes into sleep, there is no volume. This happens when I close the flap of the laptop and open it. Sometimes, the volume icon is disabled. Every time this happens, I have to re-start the laptop and then the sound is fine. Lately, even when I re-start once, there is no sound and I have to re-start again (resulting in 2 re-starts), which is annoying.

(2) Laptop crashes during software updates and wont start: Only the first software update from Yosmite (to something) went smoothly. Later, whenever I do a software update, my laptop crashes and wont start. I get a blank screen. It just won't on. Every time this happens I have to take this to a computer expert in my office, he does some magic and it starts. I asked him how to restart and he says I have to press alt+R+start button. He told me to never do any software updates, and did not provide any reasons. I have not tried the alt+R+start button because frankly I am afraid of doing more software updates and what if the computer never starts.

So I am thinking perhaps going back to the original Yosmite will eliminate the above two issues? because when Yosmite was there, I had no problems. But I want to know the risks.

(a) will going back to yosmite also crash my laptop

(b) what are the potential risks of going back to Yosmite

(c) do you have any other solutions for the above (1) and (2)

Restore your backup.

Restart your mac. As it restarts, hold down the Command and R keys together until the Apple logo appears. After a while, you'll see a screen that offers a few choices (Disk Utility, Reinstall OS, etc...). Click on Reinstall OS, and choose Yosemite.

Basics are the same.

OS X El Capitan: Revert to a previous OS X version

Hi All,

Problem is I get a message reading "This copy of the application "Install OS X" is too old to be open under this version of OS X" (that is Sierra).

Trying to connect to a Time Machine backup results in a reject too.

The bootable USB drive I've created doesn't show in the bootable drives either…

What can I do?

The Cmd-R way only installs a Sierra system, no choice, no luck.

What happens when you try to use the restore from Time Machine option? What gets rejected?

If all else fails, try booting into Internet Recovery (command - option/alt - R on a restart). It is a slow process. This will install the OS that the computer shipped with. You can then try to upgrade from there.

Hi again! I can't remember accurately the reason why the Time Machine BU did not connect. (I've done so many things in the meantime.) Thinking to that, it might be that the BU was not the one expected (other name and user). Don't know.

As for the OS that the computer shipped with, it is Sierra. A Mac reseller told me there were no problem downgrading (via a USB device) but no way. Well, I've gone ahead with Sierra now cause I cannot spend too much time on it. We're a small business and I was hoping having all the Macs under Yosemite.

Thanks for your input. And if happen to think of a solution, please post it. Who knows? Maybe it won't be too late after all.

A 2010 iMac didn't ship with Sierra. Sierra was released this year. If you have previously downloaded Yosemite, go to the App Store and download it. You can make a bootable USB stick to install using this free program which will do all the work for you. Boot off the USB drive, erase/reformat the disk, and then install Yosemite.

Bootable USB Flash Drive – Diskmaker X oruse Apple’s method Create a bootable installer for OS

Hi Eric,

Sorry, my config is not the same as the one of OP's. We bought the iMac last week so it shipped with Sierra.

I've tried to create the bootable USB stick with Diskmaker X 6 but it failed (2 or 3 times) for I don't know what reason (I erased the stick as usual, rightly formatted it, etc.). It's a mistery to me. Then I tried the Terminal route. The bootable stick was seeable on my Mac under Yosemite, but then plugged in the new iMac, it was just impossible to boot on the Yosemite sys. (The stick mounted correctly but the system was not seen as such, as bootable.) Most of the time sth like "the system on this Mac is newer and cannot deal with the older one" was showing.

I even erased the HD on the new Mac hoping Yosemite sys would then be seeable, but no way. So I reinstalled Sierra by Option-Cmd-R on reboot. It took at least half an hour (when it said 2 minutes). I feel like I simply cannot install Yosemite on the new machine for whatever reason (would it be a hardware reason?).

You can not install a version of OS X that is earlier than the version installed on the machine when it was new. Yosemite is earlier than Sierra.

Oh! OK. I was told I could so the guy was wrong. Never mind! Things seem to be OK. Thanks for for your replies.

Apple Support article.

Install OSX Restrictions