Catalina installer app too old to be opened on this version of macOs.

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Level 1

11 points

Catalina installer app too old to be opened on this version of macOs.

I have 2015 Macbook Pro with Big Sur and wish to downgrade to Catalina, as BS does not work for me. Following Apple file "how to downgrade your mac from macOs Big Sur back to Catalina" found elsewhere on this website I have been trying to dload Catalina from the App Store, and get "no results". I eventually found another site (can't remember where) and got the above message. See attachment for exact wording.

I have backed up the mac to iCloud, and need now to get the installer.

Any Advice please?

Does Apple have any intention of fixing BS?

It was touted as OK for mid 2015 MBP, but is a big flop.

It seems there is no simple way of dumping BS and reinstalling Catalina.

Every time I look on websites there are more suggestions for doing it, and I do not know what to trust.

MacBook Pro 15″, macOS 11.2

Posted on Apr 4, 2021 3:02 AM

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Answer 1

Top-ranking reply

Calvin_BT

Level 3

664 points

Apr 6, 2021 10:10 PM in response to Bob593251

That is not the way to make a bootable usb installer.

Check here - How to create a bootable installer for macOS - Apple Support

Before you start that:

Plug a Sandisk 32GB into your mac
Open Disk Utility
Select your Sandisk
Click Erase
On the Format, select Mac OS Extended (Journaled)
Click Erase
You may now proceed in the website above

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Answer 2

dialabrain

Level 10

136,385 points

Apr 4, 2021 3:33 AM in response to Bob593251

Once you download Catalina it will give you the error message. Once you click "Quit", "Install macOS Catalina" will be in the Applications folder and you can proceed to make a USB Bootable installer.

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Answer 3

dialabrain

Level 10

136,385 points

Apr 6, 2021 10:12 PM in response to Bob593251

You're welcome. You don't create a bootable installer by dragging the file onto a flash drive. First, you need to format the flash drive as GUID/Mac OS Extended (journaled), then see…

How to create a bootable installer for macOS - Apple Support

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Answer 4

Owl-53

Level 10

104,389 points

Apr 7, 2021 4:07 AM in response to Bob593251

When restating with Option key held - It will present two options. One is Internet Drive Two is the USB Installer called Install Catalina. Choose the Install Catalina Drive to startup from. Then choose Disk Utilities>> View >> View ALL Attached devices. Now maneuver to the Upper Most Internal Drive my name, usually Apple SSD ( Nothing listed below it - those are Volumes not Drives.) That is the Drive you want to re-format and choose APFS format and GUID Partition Map and Erase. Once done, back out of Disk Utilities and presented with option - Choose Install macOS and follow prompts until it reboots several times and eventually present the Setup Assist for Catalina.

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Answer 5

Bob593251 Author

Level 1

11 points

Apr 6, 2021 9:48 PM in response to dialabrain

Thanks dialabrain, i have dloaded the file install macOS Catalina.app from the App Store.

It's vollume is 8.26 GB.

I bought a Sandisk 32GB thumb drive and tried to drag the .app over and I get the message that it can't be copied because the Sandisk is too small. See attachment.

How big does the Sandisk have to be?

Bob

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Answer 6

Bob593251 Author

Level 1

11 points

Apr 7, 2021 3:45 AM in response to dialabrain

Thanks dialabrain and Calvin_BT:

Ok got that and after several hours I had the bootable disk with Catalina installed.

Then i shut down and restarted with bootable inserted, and selected Restart while holding down Option. Now the problem. I started thru the permissions and selected Mac OS Utilities- install macOs, of the 4 options. (This is on my iphone otherwise i’d include sshot). Then it went to “select the disk where you want macOS installed”. There was one option which was greyed out and said 30.42GB TOTAL, 21.76GB AVAILABLE. This was the only option. When i clicked it said “ locked”. I presume it refers to the 32GB thumb drive. If so, what capacity thumb is required? I read somewhere that 15 GB is all that is needed , so I am a little confused. In the instruction “how to downgrade your mac from macOs BigSur back to Catalina”, I am stuck at Step 4.7. Can you please help?

Thanks.

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