Cannot update macOS

MacBookPro15,1 is a MacBook Pro 15” from 2018 or 2019.

Was this a new purchase from Apple or an authorized reseller, or was this MacBook Pro acquired used from a third party?

Do Diagnostics report anything interesting?

Any network filters or content filters either installed on the Mac, or installed on the network, or implemented using the DNS server setting?

Any add-on VPN client apps, or VPN connections, in use?

Any add-on cleaner apps, anti-malware apps, add-on anti-virus apps, or add-on network firewall apps here?

Download and run EtreCheck. Then open a new reply here and then press the button that looks like a printed page to get a text input box big enough to paste the hardware and software configuration report here.

Logging Apple feedback goes to Apple, and Apple typically doesn’t then provide feedback to the submitter.

Why are you wiping your mac to install an OS there is no need for you do that.

If you want to upgrade to Catalina click on the link below.

Open Safari do not use Firefox,

How to upgrade to macOS Catalina – Apple Support

go to Section 4 and click on Get macOS Catalina.

You will be directed to the App Store it should

say Get or Download.

Before upgrading make a full back up of your Mac.

Check that third party apps you use have updates available for the new OS.

https://roaringapps.com

Check that your printers/ scanners etc have updated drivers and software available for the new OS.

Connect your mac to your router via cable rather than rely on WiFi.

Do not use your mac while it is downloading

and do not use any other devices that share the same internet connection.

If the App Store says ‘Open’ then it is detecting a previous download of the install app

go to the Applications folder locate Install macOS Catalina.app.

Move it to the Trash, empty the Trash.

Restart, click on the link again, the App Store should say ‘Get' or 'Download'.

If you are considering upgrading to Catalina be warned that it does not support 32bit apps.

Your Mac is probably running 32bit apps and these will need to be updated to 64bit apps,

some updates may be free, some may be paid. Use this app to discover which apps you have

are 32bit, https://www.stclairsoft.com/Go64/. Once the list has been created you can then

contact the developers of the apps to see if they provide 64bit updates.