I want to go from Catalina back to Mojave

[hcaroselli]

Hello,

A couple weeks ago I installed Mac OS Catalina 10.15 and I am unhappy with the way it is working. I want to go back to Mojave 10.14. I started another thread and some one sent me a link to a Mojave installer. I downloaded it and it will not run. See the attached file. How do I go backwards from Catalina 10.15 to Mojave 10.14.

Please advise.
Thank you.

 

[DeltaMac]

The simple method:
Use that Mojave installer to make a bootable Mojave installer. An 8GB or 16GB USB flash drive would be ideal. Follow the steps to make that installer from the Apple support page.

Create a bootable installer for macOS - Apple Support

You can use a USB flash drive or other secondary volume as a startup disk from which to install the Mac operating system. These steps are primarily for system administrators and other experienced users who are familiar with entering commands in Terminal.

support.apple.com

Or, you can use a dedicated app that makes that easy - such as DiskMakerX
(download version 8.0.3 for Mojave)

Boot to that installer that you created. Open Disk Utility, and erase your boot device.
When that is complete, Reinstall Mojave on that erased drive.
Restore from your backup
You really don't have other choices, such as installing Mojave on your Catalina system.
Catalina makes TWO partitions during an upgrade from an older system, which makes a "downgrade" on an existing Catalina system to a Mojave system not a realistic goal. You have to erase the existing boot device (which will delete both partitions in the process)
This assumes that you have a full backup from before you upgraded to Catalina. A Time Machine backup will work, as I have done just that a couple of weeks ago for a friend. All went well, and the Time Machine backup helped a lot.

 

[fisherking]

or you can tell us what problem's you're having, and get help here with that... and move forward. just a thought

 

[MacManiac76]

You need to create a bootable USB installer to install Mojave again. It will not run from within Catalina.