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I successfully updated to High Sierra from El Capitan (10.11.6) after this error by:
- going to Finder
- searching for "Install macOS" on "This mac"
- deleting the only result
- going back to App Store
- downloading High Sierra again

Hope this solves your problem too!

My Issue looked to be a problem with my iMAC being in DEP... I removed it from DEP, takes about an hour or so to sync and now it is installing. So not sure if it was DEP issue or if Apple Fixed something but I am working so far now.

I had just a quite long chat with one of the Apple Advisiours about this problem. After i tried everything he contacted one of Apple Senior Advisors who said that a couple of people reported this issue already the past few hours. He even said that Apple's Techninal team was looking into it and is working on a solution.

So it looks like you can't do anything about it. Because it's probably a problem on their (apple) side what will be fixed quite soon. When i asked of he could give me any approximation when the problem will be fixed he said that it normally will cost s a couple of day to fix problems like this.

Everyone here is a user just like you and we do not know how fast or slowly Apple will take care of a particular fix. You may wish to contact Apple support and ask them yourself.

It was fine for me 2 days ago but get this in the past 24 hours when try to re-install High Sierra.

I have the same problem, please I need help

I am seeing this issue on multiple systems again this morning. Any update?

I am having this same issue today. I am guessing apple still dont have a fix for it?

I tried this on two of my laptops and it's still not working.

Mine just started working again

Yes! same here.

I have this problem too, haha.

Apple Servers is down again?

And it’s downloading now, fingers crossed no errors jump out.

I got the same problem today after an installation update failed. I did have the latest OS. Got a black screen with a crossed over circle icon "ø "after logging in. Reinstallation of OS required according to Apple support.

I've seen that error several times over the last 2-3 years when trying to install a major update from App Store's "Update" page. If I go to the main or "Featured" page and select the OS update from the small-print list on the right side:

it always installed properly.