The OWC Aura blade SSDs require the following in order to be functional: "macOS 10.13 High Sierra (or later macOS) must be installed on the host computer before installing the Aura Pro X2 SSD. These OS versions include an EFI firmware update for your host computer. Without the update, your new Aura Pro X2 will not function..." It sounds like you had macOS 10.11 installed on your previous drive. That means, in order to use the Aura drive, you will need to install a working OEM Apple drive, install macOS 10.13 High Sierra or later, then remove the OEM drive and install the Aura drive. Then it should work as expected.