Downgrade to Catalina

I am trying to wipe a new laptop with Big Sur and install Catalina, but I get this error when imagr says preparing Mac OS installer:

Exception Type: EXC_CRASH (Code Signature Invalid)
Exception Codes: 0x0000000000000000, 0x0000000000000000

Termination Reason: Namespace CODESIGNING, Code 0x1

any clues?

Thank you!

i recommend creating an external drive with catalina recovery (you can do this right in MDS), boot to it and run the workflow from there.


I did but now the automaton is not working and there is no option to tell it to boot from the usb
I hold the option key down but automaton is going to internet recovery, then if I take it out so I can boot from the usb and connect it while I am on the recovery environment already, is not starting

can I possibly customise the automaton to press the keys I want? like instead of cmd+R to just hold down the option key?