Installation error macOS Catalina (null) after download.

Hi, I have tried this multiple times. Saw another post where the user said it worked after multiple times but it didn't for me. I've tried creating a brand new user. Have tried switching users. Have logged out of iCloud and relogged in. I've verified permissions. Still, get the same error each time.

It downloads the 8.09 GB install files and then just states (null) and asks to upgrade now. Which when clicked, starts the process again.

Any ideas?