Chosen Solution

Mojave installs just fine on an external drive, the when put into the machine it destroys the drive to the point of being unable to even format it or even see it. When trying to install internally I get the popup, “You may not install this volume because the computer is missing a firmware partition.” If I install a partition with Disk Utilities I get the same thing. If I run into someone who helped write High Sierra or Mojave and included these obstacles to make older Macs obsolete, is it Justifiable Homicide if I strangle them with my bare hands? Or should,I just carve an Apple logo into their foreheads? I have five machines MBP 2011-12 on my bench right now that were upgraded with Seagate SSHD drives. All are now non-functioning because of High Sierra updates and I can’t fix them. I’ve already replaced about a dozen drives out of my pocket because of this. I sent emails out to all my customers with SSHD drives not to upgrade a couple of months ago. UPDATE OK I tried just a standard Apple 500 GB drive. Formatted it externally. Put the drive in the MBP 13” 2012 non-retina machine and get the same “You may not install this volume because the computer is missing a firmware partition.” So Pulled it wiped it again and put it in the machine. Did an internet recovery and install the original Mavericks. Dropped on downloads od El Capitan, Sierra, High Sierra, and Mojave. Will install them all in order until I get a failure and report back. @ajcooke01 @danj Still think Tim Cook would look good to me with that Apple carved into him. UPDATE El Capitan installed, no problems but noted no firmware updates. Going for Sierra now. Sierra OK, doing the updates now. UPDATE 10/5/18 Took the standard Apple branded Seagate MX 500GB all the way to Mojave and it’s running OK. Now I tried a clean install of Mojave on a Seagate 500 GB SSHD older model. and all went slick. Did Migration. Now when I try to start, it takes forever for the loading progress bar to complete, especially the last quarter of an inch and NO JOY. Cannot get it to fully boot. Will be trying various cures today. This is really depressing as I have installed a couple of hundred Seagate SSHDs both the FireCudas and the older models. When trying to boot in Safe Mode, I get the Apple logo flash on, then a circle with a line through it, then it starts to load, get 1/3 of the way and the machine shuts down. UPDATE 10/6/18 I put the stand drive back in internally and it booted just fine. Hooked up the SSHD externally and repair attempts failed. It did show up titled as APFS Media. So the software install has put that APSF on again. After four attempts I was able to reformat it OS X Mac Extended. @danj, not sure what to try now except to take it down to Sierra. Any suggestions?

@mayer - Hold on here! You’ve thrown the baby out with the bath water! Lets back up…. Apple applies EFI updates with EACH OS release! So the root issue here is the system does not have the REQUIRED firmware to work. We hit this already with HFS+ to APFS with High Sierra. Where people would have updated their system and then they needed to replace the logic board and BAM! dead system as the drive was updated but the new logic board still had the older firmware. So the only way to upgrade the logic board is to install a spare drive or use an external, then you have to go through the OS install process. So you’ll need to do the same with a standard drive. Then lets see what happens then.

Dear all, I had the same problem. Macbook Air 2013, internal SSD failed, and too expensive to be replaced. So I bought a 256GB Sandisk USB to install MacOS. Initially, I Command-R to boot into recovery and tried to reinstall MacOS, but original was Mountain Lion. Installation was successful, but I wasn’t able to further upgrade to Mojave due to “.. missing firmware” issues. Here is how I resolved: created Mojave bootable installation USB driveBoot into system with the above USB driveBefore attempting installation, make sure to use Disk Utility to Erase/Partition the drive (USB thumb drive in my case) to APFS - IMPORTANTExit Disk Utility, then click on MacOS install, which would proceed with the installation file from Step 1 bootable installation USB drive worked for me, hope that helps!

Aha, OK. After some sleuthing it looks like you are kinda stuck now. I just tried to replicate the same situation you have here, and I got the same results. I attempted install Mojave on a SSHD I had laying around, booted from it externally on my 2012 MBP perfectly, but when I tried an internal boot on the same machine it threw a giant hissy fit and gave me that error you stated. That is one big fat L for the average Joe, and a giant nail in the coffin for Mac Laptops 2012 and earlier. Unfortunate! You are not alone!

I solved this, was super easy. Partition as GUID with one smaller partition I did 1GB to overkill as MSDOS (FAT) labeled it EFI. The second partition APFS. Voila all the modern ones will install. The confusing thing is that Apple calls the EFI partition a firmware parititon. I guess this is because if you use apple partition format and APFS the hardware cannot find a boot partition. So with the newer OS you have to create two partitions. You can do it all from Disk Utility on a USB installer or from macOS on a second drive. Everyone is just so frustrated because Apple hasn’t helped find the solution but I was happy when it turned out to be so simple. Hope that helps someone else.