Can't Update to Latest High Sierra or Install Mojave

[DVNIEL]

I was gifted an iMac Pro but for some reason I cannot install the latest High Sierra or install Mojave.

These are the things that I've done so far in attempting to install.

- Updating from the App Store, downloads but does not install, gives me error 602
- Read that error 602 is because of network issues, tried to install via WiFi and Ethernet, no difference
- Tried to install Mojave through App Store, installs, but at 15 seconds left says there was an error, try to install later
- Created bootable USB installer of Mojave, booted into it, says that an update is required to use this installer, connects to the internet, downloads, but errors out
- Did both methods of SMC reset: holding power button for 20 seconds and powering up, and also the power plug method...... nothing.

I'm all out of ideas..... anyone run into this problem or have an idea what I could possibly do? Thanks!

 

[Fishrrman]

Does it boot now?
What version of what OS is on it?

 

[DVNIEL]

Yes it boots and I’m on 10.13.6

I cannot seem to install Security Update 2019-005 10.13.6 because it gives me error 602

When I try to install Mojave, at the last 15 seconds I get the “an error occurred installing macOS. You can try again to complete the installation”

 

[DVNIEL]

Welp... looks like I’ll have to leave this chapter unfinished as I was able to install Catalina.

F***ing Catalina Wine Mixer.....