I'm attempting to sign in to the App Store with my Apple Account so that I can install MacOS Catalina. It tells me that the credentials are wrong but I receive a message on my iPhone and Apple Watch that someone is attempting to sign in and it even gives me a verification code. I tried signing in to iCloud in System Preferences but it was the same, instead without a message to my devices.
Earlier Mac models
Yosemite is so old that it is possible that it cannot access the App Store any more.
If your Mac is compatible with Catalina, what you could try is doing the upgrade in two steps:
If you can upgrade to Sierra, you might want to make a bootable clone backup of it before proceeding to upgrade to Catalina, just so that you'll have that much progress saved in case something goes wrong.
macOS Catalina is compatible with these computers - Apple Support
Yosemite is so old that it is possible that it cannot access the App Store any more.
If your Mac is compatible with Catalina, what you could try is doing the upgrade in two steps:
If you can upgrade to Sierra, you might want to make a bootable clone backup of it before proceeding to upgrade to Catalina, just so that you'll have that much progress saved in case something goes wrong.
macOS Catalina is compatible with these computers - Apple Support
Thankfully Chrome on Yosemite allows me to access semi-functional websites so I was able to download Sierra. Upgrading to Catalina now, thank you! Is there no longer a way to mark a response as the answer?
Sign in fails on App Store with MacOS Yosemite
