Hi Quinn, Thanks for your reply! I was also advised to submit an enterprise bug report, which is FB15802246. Sorry I'm new to the forum, and bug reporting so wasn't sure what is the best way to proceed. Fingers crossed for this being fixed. Thanks, Csaba

Pressed "Accepted Answer" by mistake for the previous post. 🤦‍♂️ This is not an answer but additional information I wanted to add. I need a form moderator to change that (remove the accepted answer flag) for the reply above.

Article by Howard Oakley on the subject: https://eclecticlight.co/2024/11/14/m4-macs-cant-virtualise-older-macos/

there is a collection of older ipsw files here: https://mrmacintosh.com/apple-silicon-m1-full-macos-restore-ipsw-firmware-files-database/

@matthewruzzi There is a link collection at Mr. Macintosh's website: https://mrmacintosh.com/apple-silicon-m1-full-macos-restore-ipsw-firmware-files-database/