Today, Apple re-closed the iOS 17.3.1 signature verification channel, and you can't downgrade to that version after you close it!
It is not surprising that Apple closed the verification channel of iOS 17.3.1 again today, after all, iOS 17.4.1 has been released in two consecutive versions, and the beta version of iOS 17.5 has also been launched.
If the current Apple version is not good, how can I upgrade to the latest version or other versions?
At present, the Tenorshare iPhone Repair Tool has provided the function of upgrading and downgrading the version, and users in need can upgrade/downgrade the version after connecting the device
1. Open the Niu's iPhone Repair Tool, connect the device to the computer through the data cable, and click "iOS Upgrade/Downgrade" at the bottom of the tool interface.
2. Click "Upgrade" on the tool page, select the version that needs to be upgraded, click on the upgrade and wait patiently for it to be completed!