Today (june 24, 2020) unable to successfully make any full installer work.
The Download macOS in MDS3, when I choose Catalina 10.15.5 2020-06-15, gives me an error about allowing mdshelpertool Full Disk Access. But I’ve done that.
I am trying to save to a folder on the Desktop. Still gives error after permission for Full Disk Access.
Other web searches tell about the softwareupdate command in Catalina.
So I try softwareupdate -d –fetch-full-installer –full-installer-version 10.15.5
Install failed with error: Update not found
Has Apple broken all of the full installers?