imac pro 10.13.4 error 602

Not sure if this will help your cause, I had the exact same issue and it took me forever to figure out what to do, most of the time I just ignored the upgrades as nothing worked.

Tried the “solved” option, didn’t work straight away, but it did work in the end.

Steps that I took, I can’t guarantee they’ll work for you.

1. Login to safe mode, disable auto-proxy, go to your wifi and disable the auto proxy under the proxy setting.

2. Restart, go to recovery mode so hold down COMMAND+R and within recovery use terminal and type “csrutil disable”.

3. Restart back in to normal mode.

4. Restart back in to recovery and use the same command “csrutil enable” but change disable to enable.

5. Re-run the setup.

I did this and it worked for me, not sure if there’s is a glitch in the installation but it was the only thing that worked for me after numerous attempts so it could also be simple an issue with the secure boot part so you could try and ignore the other steps as I did leave wifi on and it still worked so to me this is all about trial and error.

But as an FYI I did download the combo file to achieve this and didn’t rely on the auto update from the App Store.

Like I said it seems to be related to secure boot and not so much the proxy or wifi side of it.

I'm having trouble booting into Safe mode. I thought it might be the wireless keyboard, but even holding down "shift" on a wired keyboard on my iMac Pro doesn't work.

The command sudo nvram boot-args="-x" suggested on the Apple Support page for Safe Mode, also does not seem to work on an iMac Pro.

Any suggestions? Is there a magic time to press the shift key? Without the startup chime it is hard to know when!

I finally figured out that I was confused about Safe mode booting when File vault is on. When you hold down the shift key, you very quickly get to a login screen, with NO INDICATION that you will boot into safe mode. It is only after you type in a password that the computer takes a long time booting, and shows "Safe Mode" in the upper right part of the menu bar.

So I was just restarting over and over because I got to the login screen and I didn't think the key press had registered. Seems to me like it might be nice for the OS to let you know.

Try the 10.13.4 Combo Update:

Download macOS High Sierra 10.13.4 Combo Update

Contact Support. Use the link in the upper right hand corner of this page.

I had same troubles on my iMac Pro. If you are working under proxy network condition, please change network. My case, it worked.

I meant "Shift" to get into safe mode....not "s".

Tried this, no success for me.

Apple Support recommended reinstalling via online reinstaller but this just reinstalled 10.13.3 for me.