After installation of 12-3 on my iPhone SE I had “No service” from Telstra in Australia, it came back after I
shutdown and restarted the phone
Yeah this behaviour is often had on iPhones. For O2 UK, I just wait 30 secs and signal returns, with no restart. Also you may get the new voicemail messages notification happen (but it’s only telling you it’s re-enabled again following the software restart).
But as ever, YMMV depending on your network/carrier.
Les, I don’t think you can transfer a subscription to channels, but I’m going to ask Apple.
Duplicates problems like this are a pain. As you don’t know if you should or shouldn’t delete the duplicates straight away.
If you do, then will everything be fine again, or will you open the app a few days later only to find it’s deleted the originals as well – as the ‘syncing system’ thought that’s what you were actually doing!
If you don’t, then how long do you wait for the ‘syncing system’ to fix the issue, before taking steps above yourself to do so?
I guess having a backup before updating any software, and then doing the duplicate removal, gives you the best option of later recovery. Or you could just recover from the backup straight away, perhaps, and let that re-sync across devices.
Recovery from backups are not always as easy a process to deal with, as when you don’t know which of your thousands of files may or may not be missing somewhere in your directories without manually checking (and manually checking is really impossible, as you cannot possibly recall every file you have on your machine!), how can you be sure you haven’t lost something somewhere you didn’t notice until years later. 
Where did you find the “iTunes Device Support Update”? I don’t see it in System Preferences > Software Update on a Mac that was updated with the combo macOS 10.14.5 updater.
It was offered by Software Update on a Mac running 10.14.4. I could imagine it being bundled into the combo update for 10.14.5—I was surprised it was separate.
In an update that appeared alongside macOS 10.14.5, Apple has released iTunes Device Support Update, a 108.3 MB download that supposedly “ensures proper updating and restoring for iOS devices using iTunes for Mac.” It’s probably worth installing if you use iTunes to manage your iOS devices.
I wonder if this might help with the iPhone syncing bug “could not be synced because the sync session failed to start” that several SE and 6 owners ran into lately.
Thanks for the clarification.
After monitoring forums like Macrumours I decided to download and start installing the macOS Combo Update ( https://support.apple.com/kb/DL2000 ).
My Macbook updated with no problems (so far). My reserve iMac froze during the restart. I forced shutdown (holding power button for several seconds), powered up and it has resumed the update. I am waiting to see if that is successful before updating my main iMac.
Update: All seems fine with the iMac 
It has always been separate because it is necessitated by an iOS update, which has historically occurred on a different date from macOS updates. This time they happened on the same day. What I found unusual was that it required a restart, which previously hasn’t been seen.
My El Capitan machine told me today I have updates available. I figured it was some app or another, but it turns out it’s iTunes Device Support Update. I was pretty surprised at Apple doing an update for El Capitan.
It’s actually an iTunes update, required because of the iOS 12.3 update and iTunes is still being updated for Yosemite and above.
So does that mean I’ll get a new iTunes? I’m still using the special version that allows managing apps and don’t really want to give it up. If so, and I decide not to install the iTunes Device Support Update, will my current iTunes not see any iDevice I update to 12.3?
I doubt that Apple will continue to support 12.6 beyond it’s current version. I have no idea whether El Capitan will get updates beyond 12.8.2
I suspect it will always be able to see those devices, but not be able to fully interface with any changed or added features.
With past Mobile Device updates, they were silently downloaded and installed in the background. This is the first I recall being offered as a Software Update choice and also requiring a restart. I suspect you got one back in March on the day iOS 12.2 was released. Check System Information->Software->Installations for “Mobile Device” to see.
I updated using the Combo Update for 10.14.5. However, I couldn’t find a separate iTunes Device Support Update. I searched for Apple Downloads and couldn’t find it on the Apple Support site and the article doesn’t have a link for a separate download. Unfortunately, I didn’t check my iTunes version before applying the Combo update, but my iTunes version is 12.9.5.5. What version is the latest for iTunes? Is there a link for a separate download for this iTunes Device Support Update?
I don’t either, I’m just wondering if installing the current Mobile Device update will replace the 12.6.5.3 I’m running now. I do have some clones, maybe I’ll boot from one of those and install the update and see what happens.
I have… none. At all. Going back to 2015/12/29 (which must be when I started fresh). I do have a bunch of iTunes updates, the last with a version being 12.7. The two after that without versions might be the 12.6.5 ones. Lots of other things as well, but no Mobile Device.
Does anyone know if this iTunes update has been vetted for 100% reliable synching via iTunes USB to the local computer? I refuse to use the cloud (too many bad experiences and data loss), so I ALWAYS back up and sync to my local computer via USB… does this update keep that intact?
Using USB backup right now. It is giving an error message ‘Attempting to copy to the disk “Macintosh” failed. An unknown error occurred (-54)’
It seems to have completed the backup anyway but there is no easy way to test this without risking corrupting my iPhone.
I updated my iPhone 10, iPad Mini 4, & iPad Mini 5 to iOS 12.3 and they all sync fine with iTunes 12.6.5.3 on my iMac 21" running El Capitan. However, I won’t be adding this “iTunes Device Support Update” until I can be sure it doesn’t screw-up iTunes 12.6.5.3.
The 10.14.5 update contained the latest iTunes Device Support, so you didn’t need it.
Also, it won’t show up for users that don’t have an current iDevice associated with iTunes.
Al, I just checked and there isn’t any mention of “Mobile Device” in that location.