Unable to install macOS High Sierra 10.13.3 Update

You're welcome. I do run betas and the only time I've had that message was early before High Sierra was released, and that was on a Fusion drive.

You're welcome. Glad to help. Although I'm not sure the 17C2120 build was only for the iMac Pro. From what I've read, there was an "a" and a "b" version. One was for iMac Pro's.

I have the same problem. Have downloaded from the App store (which is around 1.9GB) and from the listed link (interestingly 2.25GB) and neither works.

Didn't work for me ..

Hi

I have exactly the same issue on a late 2014 27" iMac.

Will try the suggestions above - which somehow did not show before I posted this ... (now edited)

Thanks, Dirk

In my post 12/2/18 I mistakenly entered 10.13.12 as the current operating system, the current system is 10.13.2 (17C2120). The same issue persists and I see no way to update the system to 10.13.3.

Did not work for me. Apple support has not been able to fix this yet! On my iMac (Desktop) and stuck on 10.13.2

I have the same problem on my mac : do you find a solution ?

"They talked me through uninstalling the 10.13.2 OS", how do you do this ? Do you make a new installation of high sierra ?

The solution is to go into App Store, download High Sierra and start the installer from there. It will upgrade to 10.13.3 without failing. I did this when my machine was stuck on 10.13.2, worked flawlessly.

btw, the combo update won't work

You need to read the fine print. You can't install the combo update when on 10.13.2

Download macOS High Sierra 10.13.3 Combo Update