Forbidden symbol.

[eurasian]

Hi, I have an imac 27 2019 with macOS Catalina and I want to install high sierra in an external hd, so I can play some games ... so I created a bootable USB and pressing the option key I get the black screen with the symbol of forbidden ... does anyone know what can happen?

Thanks!

 

[CoastalOR]

Hi, I have an imac 27 2019 with macOS Catalina and I want to install high sierra in an external hd, so I can play some games ... so I created a bootable USB and pressing the option key I get the black screen with the symbol of forbidden ... does anyone know what can happen?

Thanks!

The problem is that the oldest macOS you can run on a "imac 27 2019" is Mojave so the problems is booting from a High Sierra installer.

 

[eurasian]

The problem is that the oldest macOS you can run on a "imac 27 2019" is Mojave.

Bad news...Thank you CoastalOR!

 

[filmak]

You can always try running the software you need in high Sierra by using a virtual machine in Mojave, like Parallels or VMware Fusion etc.