Software Update failing on High Sierra: (NSURLErrorDomain error -1012.)

Well, we sort of finally found the problem, and I have a painful working solution to get around it, since we can't fix it.

If you are on High Sierra. and none of the other "(NSURLErrorDomain error -1012.)" thread fixes have worked for you, keep reading. I'll do my best to make this as simple as possible.

The 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.

Do you have the same problem?

1. First, I suspect you have to be on High Sierra to have the problem. I installed multiple Mojaves and they were all error-free.
2. Second, take a look at this link, first post, and the list of errors. Errors 1-3 are the easiest to test for, but maybe some of the other errors already look familiar. (see note #1 below re: testing error 2). https://forums.macrumors.com/threads/nasty-mystery-high-sierra-connection-problem.2409308/
3. Third, do all 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.

The Solution:

The eventual painful solution is to install a new copy of High Sierra and migrate everything into that one.

However, big double painful issue, some of the brand new High Sierra installations came with the same problem already. I'm not kidding. I can't explain it. I did nothing to the new installations beyond making a login to test them, and they already had the problem/errors. So, you have to test each High Sierra installation for some of the errors in the link above, until you find one that's error free (see note #1 below). The installer file isn't bad itself, because I used the same one to make my error-free installations.

Notes:

1. If you think you have the iTunes/iPhone connection issue (error 2), or you want to test for this error, make sure you have the latest iTunes version for High Sierra, iTunes 12.8.3. The High Sierra installer actually gives an OLDER version that will still fail, even when everything else is fixed. Download iTunes 12.8.3 for Mac
2. When you start installing new High Sierras, and testing them for this problem/errors, DO NOT MIGRATE/TRANSFER IN accounts during installation or setup (you can use Migration Assistant app in Applications/Utilities later on). Make a new account, and make sure it has a different name from any account you intend to migrate in later. If you migrate before you test, depending on how big your accounts are, you could be waiting FOR HOURS to get in, and the system may test bad anyway.
3. The horrible long read of how ths was all figured out can be found here: https://forums.macrumors.com/threads/nasty-mystery-high-sierra-connection-problem.2409308/

Scott Bernard wrote:

Well, we sort of finally found the problem, and I have a painful working solution to get around it, since we can't fix it.

Well, I have to revise my earlier post after further testing revealed some things, and other helpful users gave some really good instruction.

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.

If you are on High Sierra and none of the other "(NSURLErrorDomain error -1012.)" threads fixes have worked for you, keep reading.

The 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 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.) (this thread)

3) iOS 17 iPhone 12 not showing up on 2009 iMac iTunes.*

*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.

5) other unspecified "server" or "connection" errors.

3. Third, do 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 Solution:

1. 1. The eventual workaround is to install a clean copy of High Sierra.
   2. 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?
   3. 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
   4. Check the App Store software Updates section to see if the error is gone. If it's NOT gone, don't panic, just restart your system once, and check again.

a brody wrote:

If after an erase and install (there is no such thing as a clean install), and switching users you get the same symptom, it is a systems issue. I'm suspecting it is networking not working right somewhere.

https://forums.ivanti.com/s/article/NSURLErrorDomain-1012-error-when-trying-to-enroll-a-DEP-registered-device?language=en_US

No, there is no button in the OS Installer that officially says "Clean Install"... I just meant 'NOTHING from the old system was used to install or set up the new system' (except the laptop hardware of course). I bought a blank thumb drive, formatted it, then installed High Sierra on it, and chose "Don't transfer any information now". I did not use the Migration Assistant after the fact, either. Sounds pretty clean to me.

The ivanti link is regarding MDM, and my device was never managed. I don't even see a resolution in their resolution section. What am I missing?

BDAqua wrote:

I wonder if a brody forgot his cure‽

Resolving NSURLErrorDomain error -1012 - Apple Community

I gave this a run, as much as I could since I don't have all the plists. It actually made the error pop up faster, but it's still the same error.

a brody wrote:

The combo and security update can give you same effect as using software update for your computer.

But I really want to find and fix the problem, not work around it.

Well, that's not what I expected for either. Maybe because they are already installed? Trying to install on "Macintosh SSD".

a brody wrote:

Software Update only downloads the ones Apple produces.

Not true. I don't know why nobody believes me. Here is a screenshot from my clean install High Sierra Software Update that works normally, showing 3rd party apps.

Here is the screenshot from my problem High Sierra Software Update showing other app updates that recently came out and I installed before it began acting up.

But again, I'm more concerned with whatever the underlying problem is.

a brody wrote:

That's a Mac App Store update, not the one that appears on Apple menu -> About This Mac -> Software Update screen. The error is likely because the said links on the App Store are going to old links on their third party publisher site that have not been updated from the High Sierra Mac App Store. Remember, many of these developers have dropped access for High Sierra. As long as their certificates are not up to date, errors like this will happen.

That's EXACTLY the update screen from AppleMenu>AboutThisMac>SoftwareUpdate. Maybe it's different in whatever OS you are on, but that's where it is on High Sierra.

As I mentioned, I also have a clean install of High Sierra, and the exact same Updates screen works flawlessly for both system updates and 3rd party app updates. The error has nothing to do with individual 3rd party apps support.

a brody wrote:

Plugins for Safari are also likely to no longer be supported, as Apple only supports Safari on Monterey, Sonoma and Ventura.

Again, I'm more interested in solving the underlying problem, as I think it's causing other issues elsewhere as well. I can't even remember how many apps I've downloaded or for what tasks I used them. Right now, their best use is just showing up (on my clean install update window), or not showing up (on my problem system update window). That way I can compare what is or isn't working yet.

a brody wrote:

http://www.binaryfruit.com/ DriveDX can tell you how much life is left on your hard drive.

My local IT guy suggested I look into my certificates. If I find any bad ones, I could download a new copy, or copy a new one off my clean install system.

Most of the bad certificates are bad on both my problem system, and my clean system, so no help there.

I did find a few that are bad on my problem system, but don't exist good OR bad on the clean system, so I'm inclined to rule those out (see attached pics anyway).

Does this info help anything? Can I delete these bad ones? LOL

Scott Bernard wrote:

a brody wrote:

1. Delete PLISTs

/Users/<my username>/Library/Preferences/com.apple.appstore.plist

/Users/<my username>/Library/Preferences/com.apple.appstore.plist.lockfile

/Users/<my username>/Library/Preferences/com.apple.softwareupdate.plist

I do have com.apple.appstore.plist.

I DO NOT have com.apple.appstore.plist.lockfile

I DO NOT have com.apple.softwareupdate.plist

The only other "appstore" plist I have is "com.apple.appstore.commerce"

There are no "softwareupdate" plists at all.

Should I try the procedure, even though only 1 plist to delete?

No verdict on trying this with only 1 plist mentioned?

Thanks