You can make a difference in the Apple Support Community!

When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

Catalina Not Happy With 2012 iMac

TL;DR - Installer Stuck, Multiple Attempts, Recovery Mode, Erased Drive, Installed Clean 10.14 (Old Mojave), Migration Assistant Time Machine Backup Restoration, Back To Working Mojave.


--


I attempted to upgrade from Mojave to Catalina. Seemed to be installing slowly but surely. A few hours into the install process I peeked in and saw the iMac was stuck in a loop of restarting, throwing an error 10 seconds later 'Your computer restarted because of a problem. Press a key or wait a few seconds to continue starting up.' and then restarting again only to throw the same error again.


I made sure I had well over 10GB of free space for the system to work with (writing temporary files, moving data, etc). I forced the machine off by holding the power button. I disconnected any external drives (including backup drive). I booted into recovery mode by holding command+r at the boot chime. I tried to install a clean version of Catalina from recovery only to get stuck again, even after running First Aid with the Disk Utility.


I had a Time Machine backup external drive so, still in recovery mode, I launched Disk Utility and noticed there was a new Macintosh-Data volume. I deleted it. I then installed a new clean version of 10.14 (Mojave) onto the normal Macintosh volume (which in my case is the 128GB SSD + 700GB HDD in one logical Fusion volume). The other 300GB of my internal 1TB HDD is partitioned for Windows 10 Pro. I reconnected all my external drives (along with backup drive). I logged into the newly installed Mojave, launched Migration Assistant, then restored from my latest Time Machine backup.


My iMac is back to running Mojave. I will be on the lookout for future updates but let this post be a reminder to those with older hardware (Late 2012 iMac, 3.1GHz i7, 16GB RAM, Fusion Drive, NVIDIA GeForce GT 650M) that Catalina may give you a bit of trouble, and to BACKUP your system with Time Machine prior to trying out this new update.


Cheers

iMac Line (2012 and Later)

Posted on Oct 9, 2019 4:30 PM

Reply
Question marked as Top-ranking reply

Posted on Oct 9, 2019 4:52 PM

I have nearly the same iMac (only difference is the processor, mine is 3.4 GHz Quad-Core. My install went okay, but man, the computer has slowed down a LOT. Things that used to be pretty fast in Mojave are very sluggish in Catalina. I see the spinning beach ball frequently now.


Not sure why your install was such a mess, maybe the Windows partition gave it problems? I know these Fusion Drives have been problematic, but so far I haven't had any issues with mine. Glad you got everything back to the way it was. I hope Apple has an update soon to fix these problems, this is one of the buggiest OS releases I've seen in a long time. I'll probably go back to my policy of waiting until the x.1 release of a major OS version like I did in the past.

Similar questions

7 replies
Question marked as Top-ranking reply

Oct 9, 2019 4:52 PM in response to Daft Puzzler

I have nearly the same iMac (only difference is the processor, mine is 3.4 GHz Quad-Core. My install went okay, but man, the computer has slowed down a LOT. Things that used to be pretty fast in Mojave are very sluggish in Catalina. I see the spinning beach ball frequently now.


Not sure why your install was such a mess, maybe the Windows partition gave it problems? I know these Fusion Drives have been problematic, but so far I haven't had any issues with mine. Glad you got everything back to the way it was. I hope Apple has an update soon to fix these problems, this is one of the buggiest OS releases I've seen in a long time. I'll probably go back to my policy of waiting until the x.1 release of a major OS version like I did in the past.

Oct 9, 2019 5:44 PM in response to TomNYC

Ah, glad to hear it went well on your similar system - brings me hope :) I too wonder about the extra partition being problematic.


I can't help but think the Catalina slowness is a combination of the newer Apple File System (APFS) format that is tuned for solid state drives but running on a Fusion drive with a mix of spinning hard disk drive. Or maybe data is still being greatly moved around as the system optimizes itself.


I will be adopting that x.1 policy this go around!

Oct 14, 2019 9:42 AM in response to paleohunter

I am also having all kinds of issues with my late 2012 iMac. I have tried to install Catalina 2 times. I have tried a completely wiped HD and building my profiles from scratch and also tried updating over Mojave and migrating my profiles and both have resulted in issues.


First issue: iCould Drive no longer syncs or even shows the folders, yet if I try to create a new folder using the same names i used before it says the folder already exists even though I cant see it. New folders with new names never sync.


Second issue: Mail fails saying the Home folder is not large enough to download messages. There is 300GB of available space on my drive.


Third issue: Cannot down load any file, or duplicate any file larger than 20MB. Get an error message that my Home Folder does not have enough room. Again I have 300GB of available space.


Fourth Issue: Photos and Music in a continuous loop of trying to sync pictures and music files. Sync never completes and keeps starting over.


I am starting to wonder if these issues are specific to the hardware on the 2012 iMac as others do not seem to have this issue.

Catalina Not Happy With 2012 iMac

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.