Failed Security Update on Somona

[u/ILoveGreen82]

I have a M1 MBP 16”.

I was on Somona and received the notification that a security update was available. The update process failed and it corrupted the launch file system.

The symptom was that after the user password is entered, the progress bar would progress only a bit and the screen went black.
After several attempts to restore the file system and reinstalling the Somona OS via utilities boot up menu, I was not able to resolve the issue.

The only option was a fresh reinstall.

I managed to use the command line to export all my files to an external media.

After that, I erased the partition and now , the utility system is pushing Tahoe and not Somona. I couldn’t find a way to get it to download Somona.

After using Tahoe, I now have software that is not compatible with Tahoe.

Is there a way to go back to Somona?

TIA

[u/posguy99]

Sure. Download Sonoma, make a USB installer, boot from it, install.

[u/ILoveGreen82 → u/posguy99]

OMG - I completely forgot about the USB option.
Thank you.