Downgrading to Mavericks from Yosemite on latest MBA

Downgrading to Mavericks from Yosemite on latest MBA

We recently purchased (last week) several iMacs and MacBook Air computers to run an Electronic Medical Records (EMR) application for a
Medical Clinic.

Our EMR is not compatible with Yosemite and is forcing us to downgrade all the computers to Mavericks.

I downloaded from the App Store Mavericks however I can’t installed on the MacBook Airs.

When I try to start the installation the screen shows the international sign telling you that you are screwed (a circle with a cross
bar).

Any help is welcome,

Mario