How do I resolve '403:Forbidden' error when downloading Yosemite from Apple?
Get this error message when trying to download Yosemite from Apple
[Re-Titled by Moderator]
MacBook Air 13″, macOS 15.3
You can't install Yosemite on anything newer than Yosemite.
If the Mac was released with Yosemite, you can use command-option-shift-R with an ethernet or ethernet adapted connection to reinstall Yosemite.
the certificates thread may help if you can't download it.
Keep in mind that any Mac that is Yosemite compatible is also El Capitan compatible. Sierra is needed for multifactor authentication with the Mac App Store.