iTunes Error (-42408) and App Store Errors

[UtterDisbelief]

Part 1: The Problem

Running High Sierra, I recently tried to re-install an app I'd bought from the Mac App Store and received an error telling me to try again but from the Purchased page. As I was actually on the Purchased page this seemed odd. I waited overnight in case it was a server problem, but it wasn't solved next day.

Next iTunes started throwing-up the (-42408) error whenever it was opened. I wasn't able to sign in to my account either.

I tried quite a few different methods to rectify the problems:

1) Re-install an earlier point-version of macOS High Sierra.
2) Boot to UniBeast installer and use DiskUtil to repair permissions on the main drive.
3) Re-install iTunes - I was using the special, older version 12.6.5 to enable me to manage my iPhone apps and ringtones.
4) Update to iTunes 12.7 which no-longer has the app store.

So far nothing had worked. Stay tuned ...

 

[UtterDisbelief]

Part 2: The Intermission

[RANT]

Just been over to the "Dark Side" for a couple of hours ("Windows 10") and the really annoying thing is iTunes 12.6.5 still works as before over there. I am able to download and manage my iOS apps and ringtones without hindrance.

So what is Apple playing at, crippling their own software and favouring Windows? Is it just that the number of iPhone users with Windows PCs is much greater than those with Macs?

There are times when being able to browse potential iOS app purchases on a desktop is a blessing compared with trying to do the same on my iPhone's screen - people with less than great eyesight, people who prefer to read all the documentation and visit links before they buy. Why don't Apple get that? Google does and let's you browse a web-interface of their app store on your desktop.

[/RANT]

 

[UtterDisbelief]

Part 3: Nearly there ...

The reason for the problems is that Apple have changed something in their sign-in authentication code or API.

Temporarily, this cured the problems:

1) Install iTunes 12.8.2 - the last free-standing version of the complete suite.

2) Reboot and you'll find App Store functionality has been restored.

3) Next, re-install iTunes 12.6.5 taking care not to disturb anything else.

You now found both App Store and iTunes fully working - with iOS device management restored.

There's more ...

 

[UtterDisbelief]

Part 4: Apple Catches Up

As of a couple of days ago Apple has now clamped down on this workaround.

It still works for the Mac App Store but iTunes iOS app management has been blocked again.

A little experimentation shows this is an intentional server-side change. I re-installed the basic High Sierra 10.13.6 distribution, without any security updates to keep it clean as of 2018, but iTunes 12.6.5 still will not download any iOS apps you may browse on the iTunes App Store, nor any you've bought previously.

iTunes 12.6.5 for Windows does still work as expected though - at this time.

EDIT 4th June 2020:

Above confirmed again. And now it is even clearer. If you enter iTunes App Store tab and select an item to buy the page now shows a button with the title "iOS App Store Only" as its label. What is more the Search box will only search in the iTunes music or Podcasts areas. No results for the App Store at all.

This confirmed with a fresh, clean install of macOS Sierra.

 

[susudio]

UtterDisbelief, Wow!!! WowWOWOOOWOOOWOOWOW!
This is a saver! thank you sooo muuuch!!!

 

[GHender3]

I have the identical issues mentioned in your initial post, if I attempt to use Whatevergreen.kext newer than version 1.3.4. As long as I stay with 1.3.4 in my EFI/Clover/kexts, no error -42408, no problems signing in, and the Mac App Store is fine. I know about the problem with the iTunes iOS App Store. That's a separate issue. Could you share the version of WEG you are using? If I use 1.3.5 or higher, all of the above happens

Thanks