I have recently got a mid 2012 Macbook Air which I installed Lion on. I am trying to update it to Mojave, but even though it is compatible, when downloading it in the App Store I get this error message:
How can I upgrade my Mac to Mojave? Do I need to upgrade to OS X 10.8 first?
Best Answer
Refer to this macOS upgrade instructions webpage, (currently it refers to macOS Mojave):