Bootable USB Installer for Catalina 10.15.4 Error "An error occurred validating the installer data. The download is either damaged or incomplete."
Hello! I recently downloaded and prepared installation media, a USB installer as directed on the Apple support website, to install Catalina on my 2017 Macbook Pro A1708 which was running High Sierra. After installing Catalina, which went off without a problem, I noticed a few quirky issues and decided to do a clean install and not have it restore my data, apps, etc., from Time Machine.
I followed the instructions from the Apple support site to erase the disk using Disk Utility directly after boot and then proceeded to install Catalina. It gets to about 2% left to complete and gives the error:
"An error occurred validating the installer data. The download is either damaged or incomplete."
I decided to recreate the USB installer using another Macbook Pro and tried the install again, but it returns the same error.
After that, I reset the NVRAM and SMC, but the error persists.
Finally, I tried to install macOS from the internet option per the Apple support instructions and made sure the Catalina USB installer was not plugged in. The installation completes, but it will not boot. It will always boot into the restore utility and if I choose to select the boot device using the startup disk tool, it will reboot and go back into the restore utility.
It seems like there is an issue somewhere buried and inaccessible through Disk Utility tools, First Aid, and Diagnostics, as they all come back without problems or issues. Please let me know what, if anything else I am able to try. Thanks!
MacBook Pro