RoAlecu
Level 1 (4 points)
Windows Software

Q: Cannot downgrade from ios 10.0.2 to 9.3.5

Hi guys,

 

I tried for more than 10 times to downgrade my iOS software to 9.3.5, but I was only getting the "The iPhone could not be restored. TATSU declined to authorize this image on this device for this user" error.

The method I used to downgrade was to download the ipsw file and then , via iTunes, restore my iPhone. I tried both on windows and on mac, but the same error was raised. I also update my iTunes , osx , etc to the latest versions, but no effect. My iphones on which I tried to downgrade are not jailbreaked (6 and 5c).

 

Could be a problem with apple software update server ?

iPhone 6, iOS 10.0.2

Posted on Oct 23, 2016 9:20 AM

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RoAlecu

Q: Cannot downgrade from ios 10.0.2 to 9.3.5

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  • Helpful answers

  • by Niel,

    Niel Niel Oct 23, 2016 9:34 AM in response to RoAlecu
    Level 10 (314,599 points)
    Mac OS X
    Oct 23, 2016 9:34 AM in response to RoAlecu

    That's intentional. Apple no longer signs 9.3.5 for devices capable of iOS 10.

     

    (145551)

  • by turingtest2,

    turingtest2 turingtest2 Oct 23, 2016 10:03 AM in response to RoAlecu
    Level 10 (88,328 points)
    Apple TV
    Oct 23, 2016 10:03 AM in response to RoAlecu

    I'm not sure what the acronym TATSU was meant to indicate, but Apple does not support downgrading iOS. There is usually a small window of a few days after each release in which roll back is possible. I guess that once they have determined that the new build is stable in the wild they shut off access to the old ones.

     

    tt2