When I try to get mac OS Catalina 10.15 upgrade on my Mac Book Air 2017 it says that your version is too old
When I try to get mac OS Catalina 10.15 upgrade on my Mac Book Air 2017 it says that your version is too old
MacBook Air 13″, macOS 11.4
Downgrading from Big Sur to Catalina will depend if this actual computer came Pre-Insatalled with Big Sur. If it did come with Big Sur when it was New - you can not downgrade at all. Apple will not allow this.
If the computer came with an earlier version of macOS as New - then yes it can be downgraded. The easy way Revert your Mac to a previous macOS version