iphone 5s flashing error

[mumin35]

hello
ı was trying to flash my iphone5s from 10.3.3 to 9.3.5
it gives this error
Return value -1, return string {0}Apple server query failure

what can ı do ?

[kristine]

I am sorry to tell you that you can't downgrade to iOS 9.3.5 which Apple has stopped sign for this firmware.

[kristine]

And if you meet any problem of error codes on 3uTools, you can take this tutorial as reference: http://www.3u.com/tutorial/articles/206 ... es-3utools