Imac Os install issues

[GodmodeDisabled]

Good evening.

I’ve been gifted a iMac late 2013 27”.
It came with windows 10 installed but was asked to wipe it. Having a macbook pro and my wife a macbook air, she fell in love with it.

So starting to see what we can do with it, i dug around on here and saw that using oclp, that Monterey would work well and stable on it.

So i got myself the latest oclp and downloaded the Monterey, following the website instructions to the letter, i got the flash drive to boot, got to wipe the ssd installed and let Monterey install.

It never booted in to Monterey.

It just hangs. I then tried to internet restore to latest official version which is Catalina. It never completed.

I’ve tried getting Mountain Lion as it’s what it shipped with. But it doesn’t make it to the installer.

I can’t get it to boot in to anything.

I have through AppStore created a Catalina usb installer, it recognises the usb but doesn’t get far at all in installing it.

As a last ditch, i used an external drive, through my macbook installed Catalina onto it.

Through oclp got to disc utility and cloned the Catalina onto the internal ssd.

It still doesn’t boot in.

It gets soooooo close when trying to boot to safe mode but doesn’t make it all the way in.

I’ve tried changing ram as that gave an issue on an older macbook.

So far nothing has worked.

Does anyone have any info on what i could try to do on it?

Greatly appreciate Any advice

Kind regards

James

 

[Bigwaff]

What system did you download and install the OCLP application? By default, OCLP application will select the Mac model it is running on. If this is not the model for the install, you need to select the proper target model in OCLP settings. Make sure to select the USB install media as the target drive when pressing "Build and Install OpenCore". Attach the USB media to the target Mac and press and hold Option key while starting the target Mac. You will see the Mac native boot drive picker. Pick the EFI on the attached USB media. Next will be OpenCore boot picker. Pick the macOS install.

 

[GodmodeDisabled]

Thank you for your reply.

I originally didn’t change the version. But remade it for the mac which is a imac 14.2

Would the patcher prevent the original catalina from installing from usb?

 

[Bigwaff]

Would the patcher prevent the original catalina from installing from usb?

Did you hold down Option while booting iMac w/ the Catalina USB install media attached? Pick the Catalina USB install in the macOS boot picker. While booted from USB, open Disk Utility and erase the internal storage so there is single partition, then install Catalina.

 

[benholt]

Two late-2013 27" gotchas that trip a lot of people:
Storage layout — that model shipped as Fusion (SSD + HDD) in most configs, not SSD-only. If a previous wipe only got the SSD side, the HDD half can be left as a stranded CoreStorage logical member and the installer bails mid-boot with an 'unable to mount' or similar. In the Catalina installer's Disk Utility, View > Show All Devices — if you see both an internal SSD and a spinning HDD, drop into Terminal (Utilities menu), run diskutil coreStorage list, then diskutil coreStorage delete <UUID> on any stranded groups before re-partitioning as APFS/HFS+.
Also worth noting: Catalina doesn't need OCLP on iMac14,2, it's natively supported. If plain Catalina keeps failing you might be hitting a bad internal SSD — those are getting old at this point. Run First Aid on the physical disk from the installer; if it errors, the SSD is the problem, not the OS.
For OCLP + Monterey specifically — after macOS is installed, boot back into the OCLP USB and run the post-install rootPatch step, then boot from internal. Skip that and it hangs on the login gray screen right after apparently good boot, which matches your "sooo close, doesn't make it all the way" description.

 

[Fishrrman]

OP:

Here's a test for you to perform.
It will take only a few minutes, but you need to try it.

Boot to INTERNET recovery (NOT to the "recovery partition").
Do this:
- Connect the iMac to ethernet. You can use wifi, but ethernet works BETTER for this
- Have it in a powered-down state (all the way off)
- Press these 3 keys: Command+Option+R
- DO NOT LET GO OF THOSE KEYS!
- Press and RELEASE the power on button (KEEP HOLDING DOWN THOSE KEYS)
- You can let go of them when you see the spinning globe (ethernet) or you're asked for your wifi password (wifi)
- The internet utilities take a while to load, be patient
- After a while, you should see the internet utilities screen.

CAN YOU GET THIS FAR?

If you can, at this point I recommend that you
1. Erase the drive
and then
2. Accept ANY version of the OS that you are offered. (Fishrrman's "Mac Rule Number 1": A Mac that boots (to any version of the OS) is preferable to one that won't boot at all.)

Open disk utility
IMPORTANT: you MUST go to the "view" menu and choose "show all devices" to see the internal drive

Click on the internal drive, then click erase.
It looks like the "last version" of the OS that 2013 iMacs will support is 10.15 (or 10.14), so I suggest that you erase the drive to APFS, GUID partition format. DO NOT USE "case sensitive"!

When the erase is done, open the OS installer and (again) accept whatever OS you are offered.
Begin clicking through. The Mac will reboot several times, and the screen may go dark for a minute or more with no other indication of activity. Be patient.

When done, you should see the initial setup screen (choose your language).
At this point, you can "set up clean", or if you have a backup, attach that and use setup assistant to migrate from it.

Good luck.

 

[GodmodeDisabled]

Two late-2013 27" gotchas that trip a lot of people:
Storage layout — that model shipped as Fusion (SSD + HDD) in most configs, not SSD-only. If a previous wipe only got the SSD side, the HDD half can be left as a stranded CoreStorage logical member and the installer bails mid-boot with an 'unable to mount' or similar. In the Catalina installer's Disk Utility, View > Show All Devices — if you see both an internal SSD and a spinning HDD, drop into Terminal (Utilities menu), run diskutil coreStorage list, then diskutil coreStorage delete <UUID> on any stranded groups before re-partitioning as APFS/HFS+.
Also worth noting: Catalina doesn't need OCLP on iMac14,2, it's natively supported. If plain Catalina keeps failing you might be hitting a bad internal SSD — those are getting old at this point. Run First Aid on the physical disk from the installer; if it errors, the SSD is the problem, not the OS.
For OCLP + Monterey specifically — after macOS is installed, boot back into the OCLP USB and run the post-install rootPatch step, then boot from internal. Skip that and it hangs on the login gray screen right after apparently good boot, which matches your "sooo close, doesn't make it all the way" description.

So it looks like it only has an ssd and not a fusion.

It fails a usb install for catalina and for mountain lion.

I did a first aid and no errors were found.

When i did a diagnostic from boot, it told me no serial is loaded and can’t continue.

Could that be the cause for the issue?

Greatly appreciate your input and advice.

 

[Bigwaff]

Your screenshot indicate Monterey installed. You need to erase the internal storage before you can install Catalina or Mountain Lion because they are not compatible with APFS file system. Reread my earlier post.

 

[DeltaMac]

When you erase the internal storage, a good choice is to change the format from APFS to Mac OS Extended (Journaled).
If you want to then install Catalina, that install will automatically change the boot drive to APFS, giving you an older version of APFS that should then be a usable drive that you can use for Catalina. The newer APFS version that you would been using with Monterey, should, after the full erase, no longer be fighting with you every step of the way.

 

[Ben J.]

Good evening.

I’ve been gifted a iMac late 2013 27”.
It came with windows 10 installed but was asked to wipe it. Having a macbook pro and my wife a macbook air, she fell in love with it.

So starting to see what we can do with it, i dug around on here and saw that using oclp, that Monterey would work well and stable on it.

So i got myself the latest oclp and downloaded the Monterey, following the website instructions to the letter, i got the flash drive to boot, got to wipe the ssd installed and let Monterey install.

It never booted in to Monterey.

It just hangs. I then tried to internet restore to latest official version which is Catalina. It never completed.

I’ve tried getting Mountain Lion as it’s what it shipped with. But it doesn’t make it to the installer.

I can’t get it to boot in to anything.

I have through AppStore created a Catalina usb installer, it recognises the usb but doesn’t get far at all in installing it.

As a last ditch, i used an external drive, through my macbook installed Catalina onto it.

Through oclp got to disc utility and cloned the Catalina onto the internal ssd.

It still doesn’t boot in.

It gets soooooo close when trying to boot to safe mode but doesn’t make it all the way in.

I’ve tried changing ram as that gave an issue on an older macbook.

So far nothing has worked.

Does anyone have any info on what i could try to do on it?

Greatly appreciate Any advice

Kind regards

James

I think maybe you're experiencing the "Expired installer certificate problem". I have seen this myself with a couple of mac laptops from 2010-2012. The fix was to have the date/time set back a few years, and make sure the mac has absolutely no access to the internet, wifi or cable, because it will automatically set the time back to today. Later, you can let it operate at current time, no problem.

Here's what google AI says:

To bypass "expired certificate" or "damaged installer" errors when installing older macOS versions, disconnect from the internet, open Terminal from the Recovery Utilities menu, and type the command date followed by a valid 12-digit or 10-digit timestamp matching the era of the operating system (e.g., date 101412002015 for Oct 14, 2015). [1, 2, 3]

Why This Happens

• • Older macOS installers (like El Capitan, High Sierra, or Mountain Lion) rely on security certificates that have since expired.
  • When the Mac checks the current real-world date against the old certificate, it blocks the install and claims the file is "damaged" or "temporarily unavailable".
  • Forcing the system clock back to a time when that OS was actively supported tricks the installer into accepting the certificate. [1, 2, 3, 4]

Step-by-Step Instructions

1. • Disconnect Wi-Fi / Unplug Ethernet: Keep your Mac offline so it does not automatically sync back to the current time via an NTP server. [1, 2, 3]
   • Open Terminal:
     • Restart your Mac into Recovery Mode (hold Command + R during boot).
     • Go to the top menu bar, click Utilities, and select Terminal. [1, 2]
   • Set the Date:
     • Use the format MMDDhhmmYY or MMDDhhmmYYYY (Month, Day, Hour, Minute, Year).
     • Example for 2015 (El Capitan/Yosemite era): Type date 101412002015 (October 14, 2015, at 12:00 PM) and press Return.
     • Example for 2016 (High Sierra era): Type date 111213142016 (November 12, 2016, at 13:14). [1, 2, 3]
   • Proceed with Installation: Close Terminal and resume the macOS installation process from the recovery window. [1, 2]

Here are the specifications on the imac. It says it can run up to OSX 10.15 Catalina. I'd say install Catalina, a fine system version, and forget about OCLP. Unless it has been modified it will have a old spinning harddisk, so I suggest you make sure you format it with Mac OS Extended journaled (HFS+) before setting back the time and running the installer:
Everymac.com: iMac late 2013 27".

 

[winxmac]

Full APFS support started with High Sierra. Sierra and older macOS versions will only work with HFS+ or macOS Extended (Journaled).

The best way to create an OCLP bootable drive is to create it for the Mac you intend to install it to, however, if that is not possible, meaning the Mac does not have any macOS installed, on the spare Mac that you have access to, make sure to change the identifier to match the Mac to where you plan the OCLP install.

 

[Fishrrman]

OP:

Once again I ask:
Have you tried booting to INTERNET recovery, as I suggested in reply 6 above?