Mac OS cannot be installed on this computer error

[seamuskrat]

Ok- and odd one.
2015 iMac27 fully loaded.
Had a supplemental Catalina update.
Went ahead and downloaded and restart.
about 5 minutes in I get a screen saying it cannot be restarted. Press D to run diagnostics or restart the installer.
I ran the diagnostics and it said no issues. Tried installing again - no luck. Same error.
Tried option and got Mac OS and Installer. Installer gets the same issue and the Mac OS partition starts, let’s me input password then shuts down Mac.
any thoughts on how else to
Proceed? I can’t get disk utility to show to open.
I do have time machine yet it won’t recognize the drive.

 

[velocityg4]

Do you have another Mac to make an installer? You could create a USB thumb drive installer. Then perform a clean install.

Downloads

diskmakerx.com

Internet recovery is another option for a clean install. Option-⌘-R for the latest compatible version of macOS.

How to reinstall macOS - Apple Support

You can use macOS Recovery, your computer's built-in recovery system, to reinstall the Mac operating system. Reinstalling macOS doesn't remove your personal data.

support.apple.com

I like having a USB installer handy. Actually I have a USB installer with multiple partitions for a wide range of macOS versions. Also if there is an issue you won't have to start the whole internet recovery over again. You can also try to install over your existing installation and skip the whole clean install.

 

[seamuskrat]

Do you have another Mac to make an installer? You could create a USB thumb drive installer. Then perform a clean install.

Downloads

diskmakerx.com

Internet recovery is another option for a clean install. Option-⌘-R for the latest compatible version of macOS.

How to reinstall macOS - Apple Support

You can use macOS Recovery, your computer's built-in recovery system, to reinstall the Mac operating system. Reinstalling macOS doesn't remove your personal data.

support.apple.com

I like having a USB installer handy. Actually I have a USB installer with multiple partitions for a wide range of macOS versions. Also if there is an issue you won't have to start the whole internet recovery over again. You can also try to install over your existing installation and skip the whole clean install.

I’ve got an older installed handy. Trying that now. I’ll do the internet version next. Thanks. Wish me luck.

 

[Taz Mangus]

Run Disk Utility First Aid on the internal drive.

How to repair a Mac disk with Disk Utility - Apple Support

Use the First Aid feature of Disk Utility to find and repair disk errors.

support.apple.com

 

[seamuskrat]

Run Disk Utility First Aid on the internal drive.

How to repair a Mac disk with Disk Utility - Apple Support

Use the First Aid feature of Disk Utility to find and repair disk errors.

support.apple.com

This isn’t an option. It’s like that virtual drive doesn’t exist. I am running disk utility off a USB drive so some progress.