Step Eight:Enjoy Catalina without losing any data or reinstalling anything. Step Seven:Once the above SuperDuper process is complete, boot your Mac mini from your Mac mini hard drive using Startup Disk option You do this by backing up the Samsung T5 to the existing hard drive on the Mac mini. Step Six:Use SuperDuper to transfer from Samsung T5 to the Mac mini hard drive. The idea is to use the external drive to boot your Mac mini to confirm that the Catalina update is working on the Mac mini. Step Five: Boot Mac mini from the external drive by using Startup Disk option. Once the installation has been successful, shutdown your MacBook and remove the Samsung T5. The installation will take some time and your MacBook will restart many times. When the installer asks which hard drive to install in, select the Samsung T5 external hard drive. Step Four: Run the Catalina installer on the MacBook Pro. It's an 8gb file so grab a drink or watch your favourite TV show. Step Three: Download the macOS Catalina on the MacBook Pro. The Samsung T5 will show up as external hard drive on the MacBook Pro. Step Two:Connect the Samsung T5 to MacBook Pro.

Now your Samsung T5 is the replica of macOS that was running on your Mac mini. Step One: Make a SuperDuper backup of the Mac mini on the Samsung T5. Solution: Use another Mac to update from Mojave to Catalina. External drive (I used my Samsung T5 SSD) formatted in APFS.Another Mac other than the one that has this issue (in my case 2016 MacBook Pro).I did not want to lose any data, and I did not want to start from scratch on this Mac as It has been running for years and does all kinds of things and workflows that will be too time consuming to re-setup. There are several solutions that were recommended, but none I found convincing. So, I updated it, and this happened: I forgot to take the photo, so I borrowed from reddit Source: What was surprising to me, I had not updated my Mac mini from Mojave to Catalina. This means macOS Catalina will be the last Mac operating system to support my Mac mini. However, I noticed that my beloved 2012 Mac mini is no longer supported. On June 22, Apple introduced macOS Big Sur and till this very date I have mixed feelings on this recent release. This has been confirmed by my local Apple Store and I have since replaced the RAM with another set from a different third party and everything is working smoothly. I had bought non APPLE ram for my Mac Mini and although the RAM was working fine, I believe during the update process, Apple checks hardware and the RAM was causing issues. Update: I have discovered that an easy fix for this was replacing the RAM.

Mac os update