Can't restore or update IPhone - TATSU declined to authorize

Question

I'm attempting to either restore or update an iPhone 5 which won't boot. It's stuck on the apple logo boot screen. Hard reset does nothing.

I have tried normal restore mode via iTunes and DFU mode.

I'm signed into iTunes as the same apple ID as the phone.

I've authorized the mac for this apple ID in iTunes.

each time I try and either do update or restore I get the following error from iTunes:

iphone could not be restored (updated). TATSU declined to authorize this image on this device for this user.

Anything else I can try? it does not matter if I lose the data on the phone. Just needs to work again.

Also is there a way to view the boot sequence from my mac or the phone either via terminal or xcode or something so I can see where it's hanging in the boot sequence?

Answer 1

for anyone else who comes across this or something similar. It turned out that my hosts file had an entry to gs.apple.com which was causing apple's signing (TATSU) server request to fail with their not so helpful error message.

So you need to check your hosts file on the computer you are running iTunes on to see if there are any entries to gs.apple.com and then either remove those lines or comment them out by placing a # at the start of the line.

like so #gs.apple.com 74.454.656.343 easiest way is via terminal. look up how to edit host file if you don't know how. on my mac the host file was located at /etc/hosts once in terminal: sudo nano /etc/hosts will open an editor, once changed control x will exit, type y then enter when prompted to save your changes to the hosts file. all done.

Answer 2

Mac

If you're using a Mac, follow these steps:

1. In the Finder, choose Applications > Utilities.

2. Open Terminal.

3. Type this command and press Return:

sudo nano /private/etc/hosts

4. Enter the password you use to sign in to your computer and press Return. >You won't see text appear in the Terminal window when you type your >password.

5. Terminal displays the hosts file. If you don't see a window similar to the one below, make sure you're using a nonblank administrator password.

6. Navigate using the arrow keys and look for an entry containing >“gs.apple.com”.

If you don't see any entry containing gs.apple.com, then the hosts file >isn't related to the issue. Close the Terminal and move on to the next >section of this article, "Address TCP/IP filtering, firewall, or security >software."

7. Add the # symbol and a space ("# ") to the beginning of the gs.apple.com >entry.

8. Press Control-O to save the file.

9. Press Return when asked for the filename.

10. Press Control-X to exit the editor.

11. Restart your Mac.

After your computer is finished restarting, try to update or restore your >iOS device again.

https://support.apple.com/en-ca/HT201442

That being said, there is no such entry in my /private/etc/hosts or in my /etc/hosts file, so I will look for other solutions to this error.

Answer 3

I had an unusual experience that I would like to document here.

I have an iPad Mini 2 given to me that had this exact error message when using a Mac.

When moved to a PC, it gave an "Unknown error 3194."

When loaded from Software Update on iOS, I got a dialog box during the "Verifying Update" process that reported that my connection to the Internet was lost (which was not true).

The exact message is: Unable to Verify Update iOS 12.5.7 failed verification because you are no longer connected to the Internet.

After hours of thrashing, I tried to open a case with Apple, only to discover that the serial number of this device was not recognized. So, I opened the case using another device's serial number.

After some time on the phone, we discovered that both my serial number and IMEI were not on file at Apple! The signing server was rejecting my request to upgrade since my device was not recognized.

Now, before anyone asks, the serial number shown in IOS matched the one etched on the case, so there was no activation-lock-bypass hacking going on here.

The recommendation? Go to the Apple Store and have the register the serial number into the systems. I will do that in the next few weeks and will report back. Of all of the answers I found on this topic, NONE of them suggested that the serial number might be missing from Apple's databases. As a result, I leave this message here for future travelers experiencing this issue.

Try to open an Apple support case using the serial number of your device. If the serial number is not recognized, that's a strong clue that the device may experience this problem.