Turns out Parallels isn't smart enough to download a MacOS version that is SUPPORTED on the host macOS version. I needed version 26.3.1. Version downloads are here: https://mrmacintosh.com/apple-silic...4/22-,5.,UniversalMac_11.4_20F71_Restore.ipsw
Hello all, In order to investigate this further, Kindly reproduce the issue and collect a technical report. To generate the report, right-click on the Parallels icon in Dock > Help > Send technical data > check "Attach screenshots..." > press Send Report, and provide us with the report's 9-digit ID. In addition as a troubleshooting step, kindly upgrade your hostOS to the latest version and check. Regards,