It seems that several users would be reporting problems in the installation of the new macOS High Sierra and it is that an error occurs when updating the firmware. We do not understand very well the reasons for this error since it is not something that happens to all users, but the first signs point to incompatibility with the new APFS format and these SSDs.
The update starts normally on these computers and then shows an error as shown in the image that we can see in the header of this article -of the user Osiris- and the whole process stops. The error is clear: fails while "checking firmware".
It seems that there are a number of Macs that have discs with incompatibility problem and these are added a list that manufacturer OWC reported similar problems, these are:
- MacBook Air (11-inch, Mid 2013)
- MacBook Air (13-inch, Mid 2013)
- MacBook Air (11-inch, Early 2014)
- MacBook Air (13-inch, Early 2014)
- Mac Pro (late 2013)
Several users claim not to have these discs installed on the Mac and to have this same error at the time of the update. In any case the only thing we can do is use the recovery partition, backup or directly download macOS via WiFi, but little else. What is evident is that if it fails to update the firmware, we cannot upgrade the version and the only remedy for now is to wait for a patch or update from Apple. We are not going to run out of Mac in the previous version of macOS, in this case macOS Sierra.