Scott Bernard wrote:
As it turns out, I really DID have network gremlins, accounting for quite a few forum threads I started recently. I'm not sure how many of the attempts in this thread would have worked if not for said gremlins.
The eventual answer was a new installation of High Sierra (ironic in this thread at least)...
Well, I have to revise my earlier post after further testing revealed some things, and other helpful users gave some really good instruction:
This is hard to explain, but some of you may have a LARGER problem, that's giving you the High Sierra full installer download errors. I'll detail what the larger problem is, and how you can spot it below. If you check and think you have the Larger problem, I'd highly recommend you go ahead and fix it, as it will keep causing "server" and "connection" errors until you do. There are more potential errors than just the examples I give below. Fixing the Larger problem requires a clean install of High Sierra, from the installer you already want to download, and might have been planning to clean install anyway.
Thread Topic Answers:
To Download High Sierra full installer, these are the ways I would try, as posted in this thread.
More than one of these worked for me:
- Give my answer above a shot: Answer (edited)
- Give my other answer a shot: Answer
- Give my found answer a shot: Answer
- Get on a different computer to download it.
- Make a different computer to download it: I didn't post this one yet, but if you can partition a drive, or have another drive, and you have or can download an earlier (Sierra) or later (Mojave) MacOS installer, you can install that MacOS on your partition/other drive, boot it up (using Startup Disk), and go to the app store from there (using the link found here) to download the High Sierra installer. Then boot back to your current system (Startup Disk), and copy the finished download in.
Going back to the Larger problem topic:
The big discovery since my earlier post:
***ALL High Sierra Clean Installs come with the errors/problem... ...until you restart it once.***
Everything below is revised to reflect this.
We sort of finally found the main problem, and I have a working solution to get around it, since we can't fix it.
The (Larger) Problem:
It seems there is something local stopping connections to at least swscan.apple.com, but we don't know what/where it is in order to fix it in-place.
Do you have the same (Larger) problem?
1. First, I suspect you have to be on High Sierra to have this problem. I installed multiple Mojaves and they were all error-free.
2. Second, take a look at these related errors to the main problem. Errors 1-3 are the easiest to test for, but maybe some of the other errors already look familiar.
1) Can't add Google or Yahoo email accounts to Internet Accounts pane.
2) Software Update failing on High Sierra: (NSURLErrorDomain error -1012.)
3) iOS 17 iPhone 12 not showing up on 2009 iMac iTunes.*
aka. iOS 17 iPhones not connecting to iTunes, because support download fails.
*make sure you have the latest iTunes version if you test. On High Sierra this should be 12.8.3. For some users, this version never appeared in the App Store software Updates section. Get it here: Download iTunes 12.8.3 for Mac
4) Can't download High Sierra full installer. (this thread)
5) other unspecified "server" or "connection" errors.
3. Third, do errors 1-3 occur together? If you have 1 or 2 of the errors, but a 3rd one works fine, you likely don't have the problem described above, and this solution would be overkill.
The (Larger) Solution:
- The eventual workaround is to install a clean copy of High Sierra. Download full installer per options above, on this post.
- Migrate your users and data into the clean copy, but to avoid ugly permissions problems, try following the outline found here: Is there a difference in results between Migration Assistant app and 'Transfer Information' option during OS installation?
- The High Sierra installer installs an older version of iTunes. You want to install the latest version of iTunes or you may have device connection issues. On High Sierra this should be 12.8.3. Get it here: Download iTunes 12.8.3 for Mac
- Check the App Store High Sierra page and see if you can download the full installer normally now. Remember to hide the previous High Sierra installer file that you already downloaded so they don't conflict. They are usually in "Applications". I toss mine in the trash, but don't empty it. Use the High Sierra link on this page to get to the App Store High Sierra page.: How to download and install macOS - Apple Support. If you still can't download, don't panic, just restart your system once, and check again.
- If the High Sierra download is working, you don't need to finish it, but remember to pull the previous copy out of the trash if you wanted to keep it.