I can't install Mojave 10.14.6 'We could not complete your purchase'
macOS High Sierra 10.13.6 and I want to install Mojave 10.14.6 didn't doest'n let me says this We could not complete your purchase
[Re-Titled by Moderator]
iMac 21.5″, macOS 10.13
Has the User ( you ) Logged into the Apple Store using your Apple ID and Password ?
What Web Browser is being used to invoke the Download of Mojave
The Age of this computer will Govern what newer version of macOS it will Qualify to install. Use About this Mac from the Apple Icon on Desktop - the required Information will be there.
With the above information in-hand - follow this How to get old versions of macOS and verify what version this computer Qualifies to install. For Best results use Safari to commence the download as Others may not work.
Safari will open a redirect and open the Apple Store where the download can commence.
