"To install macOS High Sierra, a firmware update is required."

Hi - I have the same model Mac Pro (mid-2010, 2.8 GHz Quad) and was having similar issues - but you might want to try the following:

In the instructions in the screen shot you posted, it tells you to hold down the power button until the power indicator light flashes OR you hear a long tone.

The first time I attempted the update I held down the button until the power light flashed and then let go. The long tone happened after I let go of the button and I got a normal looking startup screen (grey Apple logo with black status bar).

Upon restart, I was just taken to the same screen advising me that I needed to update the firmware.

The second time I attempted the update, I kept my finger on the power button past the flashing power light and until the long tone sounded. Only then did I let go of the button.

This time a different (old school/low res) startup screen showed up where both the Apple logo and the status bar were grey. The SuperDrive tray opened, the status bar went to completion and the SuperDrive tray closed itself again.

When the machine restarted it took me to the screen where I could proceed to install High Sierra, which happened successfully.

I'm not sure of the technical reason why this worked, but it did. Hope it helps you too.

What finally worked for my 2010 Westmere was:

After clicking on "shut down", I held the power button until after the flashing power light, after the booooooop tone and after the OSX chime. Only then, did I get to the firmware update progress bar. After a reboot, I was able to successfully install HS.

Hopefully, this is helpful for others.

I got this to work, all I had to do was run the firmware update from an OS, not from a USB drive, You CANNOT update the firmware from a USB drive. After Apple put up El Capitan again on the App Store I simply installed that then downloaded the High Sierra installer from the App Store then ran it and boom it updated.

Hi scoogy.

I had the same problem with my 2009 mac pro. I've updated the firmware to 5.1 ages ago but trying to install this new os from Sierra to High Sierra resulted in the same issue.

The fix for me was to remove my newer non EFT nivida card and put back in the old red ATI card. Once that was done I could update the firmware and then continue with the install as per the instructions... reboot from the install prompt as per you image, on power on, hold the button past the flashes and tone then let go.

TTFN

What worked for me:

Just keep power button pressed longer! First few attempts I was releasing it after computer wakes up and starts, and was greeted by same "upgrade firmware message".

You need more! For me that was keeping the button for like 30 seconds, waiting for unusual booooooop tone, and than all worked

The issue for me was caused by my firewire external hard drive. Once I turned off the drive and booted back into the firmware update screen, the firmware loaded quickly and successfully.

The I could install High Sierra.

If you don't have the Shutdown button on the installation window available, then the firmware will not be installed. The update helper needs to copy the firmware update to your computer first, before the shutdown and boot into the firmware update screen.

I had the same issue (firmware update wouldn’t apply, even when following the instructions). For me, the issue seems to have been the third-party video card I was running (a hacked Radeon 7950 that doesn’t have proper boot-time video support). After digging up and installing my original NV120 card, the firmware update applied properly, and I’m currently installing High Sierra.

Big_Smoke1992 wrote:

I have the exact same computer, Mac Pro mid 2010. I currently have no OS installed on it so I created a bootable USB drive using the High Sierra installer that I downloaded from my MacBook mid 2010, I then booted to the installer and then chose the drive I wanted to install on, but directly after that I was greeted with the exact same message, but for me the 'Shut Down' button is grayed out so I can't select it.

That is the basic reason for your problem; the firmware update will only be performed if you shut down by clicking the button in the installer, and will not occur if you shut down the computer via the menu bar option.

If the option is greyed out in the installer, there must be some reason, like third-party hardware, that it thinks the install cannot take place.

Do you have any special hardware installed?

All I can tell you is what worked for me. Ran disk utility-checked ok- ejected hard drive #2( I have 2 hard drives in there)- when doing the firmware update, nothing else should be running at same time. Just do what it says-press and hold the power button until you see the blinking lights AND hear the long tone, then let it go-not before- then you should see the grey screen and the progress bar. I also have a dual boot video card, so I changed the switch on it from 2 to 1, and it worked. Why? Don’t exactly know/ but it did

Jb

Ugh...I bet that is my problem too. I also have a 2009 bumped up to the 5.1 firmware (in preparation for the Pindelski CPU upgrade), and I have already swapped out the 120 with an nVidia GeForce GTX 660 (which works great btw!). Glad I didn't can the old card. I will swap it back in and see if that cures the problem, and report back.

For the record, my behavior was hold the power button down (until long beep, not flashing light), computer is working for a long time, then boots back into Sierra with same message. I was always able to click the shut down button in the dialog.

Read the message on the screen.

You shutdown

Then, restart by holding down the power button until the light flashes or you hear a long tone.

The firmware update has already been downloaded and is waiting for you to install it by following the onscreen directions.

It could be that the firmware update process included with the High Sierra installer is buggy. You might try doing the firmware update separately by going here: About EFI and SMC firmware updates for Intel-based Mac computers - Apple Support

Did you replace the original hard disk with an OWC's Aura SSD?

https://www.macrumors.com/2017/09/26/owc-aura-ssd-macos-high-sierra/

Meanwhile there is a new High Sierra installer, dated October the 5th, that includes "macOS 10.13 Supplemental".

Maybe the new installer can solve the old MacPro issue.

Then it sounds like it is either not completing the firmware update, or the installer isn't recognizing that it has been installed.

You might want to take it to a Genius Bar or call AppleCare.

They might post a standalone Firmware update, but nobody here would know.