Failing at downgrading Big Sur

[annabanana311]

I've been trying to downgrade to Catalina from Big Sur for 2 days now on a brand new machine that came with Big Sur. I've tried numerous ways. Currently, I'm running into 2 issues. (Ignore the wrong screen resolution in the photos below - this seems to be an effect while in Recovery Mode only, most likely related to the KVM we use in our production studio setup.)

1) I can't erase the container. I click the Erase button, it turns blue when I click it, but nothing happens.

2) In the Catalina installer, there's no other disk option besides the USB stick. Maybe that's because I can't erase the container.

Any help would be appreciated! Thanks in advance!

Mac Mini 2018 running Big Sur 11.1
Intel Core i7

 

[posguy99]

Don't erase the container, what would be the point of that? Erase the disk.

 

[annabanana311]

Don't erase the container, what would be the point of that? Erase the disk.

I've tried erasing both (one guide said the container, another said the disk). I get the same no response from the Erase button both ways.

 

[FNH15]

I've tried erasing both (one guide said the container, another said the disk). I get the same no response from the Erase button both ways.

Try using the diskutil command from Terminal while in Recovery - worth a shot!

 

[annabanana311]

I have no idea why, but choosing to erase the "Update" disk (shown in the screenshot in the original post) seemed to do the trick. I was hesitant to do that but now my machine is running Catalina. Just fyi. Thanks for the help.

 

[Yeung]

I've been trying to downgrade to Catalina from Big Sur for 2 days now on a brand new machine that came with Big Sur. I've tried numerous ways. Currently, I'm running into 2 issues. (Ignore the wrong screen resolution in the photos below - this seems to be an effect while in Recovery Mode only, most likely related to the KVM we use in our production studio setup.)

1) I can't erase the container. I click the Erase button, it turns blue when I click it, but nothing happens.

2) In the Catalina installer, there's no other disk option besides the USB stick. Maybe that's because I can't erase the container.

Any help would be appreciated! Thanks in advance!

Mac Mini 2018 running Big Sur 11.1
Intel Core i7



View attachment 1734591View attachment 1734590

Did you solve this problem? Did you try to disable the T2 chip?

 

[russell_314]

You can’t downgrade to an OS that was before the Mac was released. If you want Catalina you’ll have to get a Mac that came with it or a previous version of macOS.

 

[Yeung]

I've been trying to downgrade to Catalina from Big Sur for 2 days now on a brand new machine that came with Big Sur. I've tried numerous ways. Currently, I'm running into 2 issues. (Ignore the wrong screen resolution in the photos below - this seems to be an effect while in Recovery Mode only, most likely related to the KVM we use in our production studio setup.)

1) I can't erase the container. I click the Erase button, it turns blue when I click it, but nothing happens.

2) In the Catalina installer, there's no other disk option besides the USB stick. Maybe that's because I can't erase the container.

Any help would be appreciated! Thanks in advance!

Mac Mini 2018 running Big Sur 11.1
Intel Core i7



View attachment 1734591View attachment 1734590

I've been trying to downgrade to Catalina from Big Sur for 2 days now on a brand new machine that came with Big Sur. I've tried numerous ways. Currently, I'm running into 2 issues. (Ignore the wrong screen resolution in the photos below - this seems to be an effect while in Recovery Mode only, most likely related to the KVM we use in our production studio setup.)

1) I can't erase the container. I click the Erase button, it turns blue when I click it, but nothing happens.

2) In the Catalina installer, there's no other disk option besides the USB stick. Maybe that's because I can't erase the container.

Any help would be appreciated! Thanks in advance!

Mac Mini 2018 running Big Sur 11.1
Intel Core i7



View attachment 1734591View attachment 1734590

I have installed the catalina successfully on the iMac 2020 which was shipped with big sur! HaHa!

 

[CoastalOR]

I have installed the catalina successfully on the iMac 2020 which was shipped with big sur! HaHa!

The 2020 iMac originally was released with Catalina macOS 10.15.6 (Build 19G2005 - a special build with drivers that had hardware support for the 2020 iMac). The current Catalina macOS 10.15.7 and newer OS would also have support for the 2020 iMac. Congratulations on the successful downgrade from Big Sur to Catalina.

 

[darngooddesign]

I have installed the catalina successfully on the iMac 2020 which was shipped with big sur! HaHa!

You could install Catalina because at one point your model of iMac was sold with Catalina, but you can't install an earlier version of OS X which your model of iMac never came with; for example, you can't install High Sierra on your computer.

 

[JohnArtist]

I found this video. I downgraded my 2018 Mac mini to Catalina for App compatibility. It came with Monterey installed. This video helped A LOT!! It uses a partition on the Mac mini's SSD instead of a bootable USB. They also show an easy way to use terminal commands for this process: