Attempts to run the Mojave installer from a Catalina Recovery (local or Internet) will also fail. These ‘solutions’ are not supportable on scale.)ĭirectly downgrading from Catalina to Mojave with the startosinstall -eraseinstall command will fail. I am aware that someone might be able to hack together a Chimera Mojave with Catalina drivers. Any new Mac models that Apple introduces from now on, will also require Catalina and cannot be downgraded to Mojave. You cannot use these instructions to force a Mac Pro or MacBook Pro 16” to boot to Mojave. The exceptions are the iMac Pro (High Sierra) and the MacBook Pro 16“ and the Mac Pro (2019) which both require Catalina. As of this writing, all new Macs require at least Mojave. Usually a Mac requires at least the version of macOS that the model shipped with when it was introduced.
Important Notice: these instructions will only work for Mac models that can boot to Mojave. If your organization has blockers for Catalina (incompatible software, etc.) you may want to install Mojave on these Macs. Apple has started shipping Mac models that used to come with Mojave pre-installed with Catalina.