Creating a Bootable Catalina installer

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Level 1

5 points

Creating a Bootable Catalina installer

I'm running Sierra 10.12.6 with the Install Catalina.app in my application folder and with a SanDisk usb stick formatted to Mac OS Extended (journaled).

Terminal command:

sudo /Applications/Install\ macOS\ Install macOS Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/SanDisk1

Terminal response:

/Applications/Install macOS Catalina.app does not appear to be a valid OS installer application.

Following a suggestion (permission issue?) found on the web I also tried this:

I copied the Catalina installer to my desktop and used this Terminal command:

sudo /Users/MYNAME/Desktop/Install\ macOS\Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/SanDisk1

Terminals response:

sudo: /Users/MYNAME/Desktop/Install macOS Install: command not found

yes, i used my real name instead of MYNAME.

I'm totally frustrated. Again.

Any help is highly appreciated.

THANKS!

iMac 21.5″, macOS 10.12

Posted on Feb 21, 2021 9:08 AM

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Answer 1

Top-ranking reply

dialabrain

Level 10

135,893 points

Feb 21, 2021 9:50 AM in response to Vortex99

See this page for the correct way to do this…

How to create a bootable installer for macOS - Apple Support

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Answer 2

dialabrain

Level 10

135,893 points

Feb 21, 2021 11:56 AM in response to Vortex99

That's why it's not working. The installer should be 8.26GBs.

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Answer 3

dialabrain

Level 10

135,893 points

Feb 21, 2021 11:08 AM in response to Vortex99

I see. What size is listed for the Catalina installer?

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Answer 4

Vortex99 Author

Level 1

5 points

Feb 21, 2021 10:50 AM in response to dialabrain

i followed the above How to create a bootable installer for MacOS -Apple Support using:

sudo /Applications/Install\ macOS\ Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/Sandisk1

the terminal's response remains the same:

/Applications/Install macOS Catalina.app does not appear to be a valid OS installer application.

i also downloaded the installer again with the same results.

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Answer 5

Vortex99 Author

Level 1

5 points

Feb 21, 2021 12:28 PM in response to dialabrain

ok, thanks for your help.

a quick search on the web indicates you need some 3rd party doohicky to get to the full installer at which point i'm calling it a day. I'm 70 yrs old and have been using inclusively apple for the last 30 yrs. I thought i'd entertain myself with Logic Pro X my last few days which requires Catalina. But my patience with Apple has run just too thin the last few yrs. So, I'll stick with my outdated Garageband and give Digital Performer another try.

Thanks again.

And STEVE, if you can hear me, PLEASE COME BACK

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